We're also still trying to pinpoint all cultural/mixed WHS to a specific century ("Built in the xth century"). Some are very difficult though. I'd like to use this thread to discuss some of the tougher ones.

First:
SGang Gwaay (Canada)
- the tiny AB evaluation only says about its origins: "The first traces of human occupation date back almost 2,000 years" - so first century AD?
- it is even more difficult to distinguish what is the defining period for this site is (where the OUV derives from) - it would be the age of the totem poles I guess, but how old are they? maybe 19th century? or do we take the age of when the custom of totem pole making started?

On the site´s website it says the totems are indeed from the 19th Century. I would stick to physical remains when it comes to dating WHSs.

Agree entirely both with Assif's general principle and the specifics in this case.
What is "on show" at SGang Gwaay is a Haida village as at the end of the 19th Century after around 100 years of contact with Europeans. That it exists in this "frozen" form reflects the impact of that contact on Haida society. This link describes an incident by which smallpox was brought to the inscribed village in 1862 which ultimately led to the end of its permanent occupation
http://www.greatcanadianparks.com/bcolumbia/gwaiinp/page5.htm

Thanks.

And can you help me think with determining the age of Richtersveld?
Quite typical of the African cultural landscape...
So what's the age of the rush mat houses?

It occurs to me that one way of handling the dates of some "Cultural Landscapes" might be to define them as "contemporary" or "continuous" UNLESS there is a good reason to find some other date/period
For instance where
a. they are "Relict"
b. There was a "golden age" e.g Blaenavon coal mining?
c. A significant number of the structures dated to a particular period.
d. The ethnic group "arrived" in the area at a particular known period

We are going to have similar problems with most of the "Wine landscapes" for instance! Take St Emilion - it represents the result of human landscape development going back to pre-history including Roman and mediaeval aspects. The wine "trade" itself only really took off in the 19th century. I might suggest that it is basically "Continuous" with a significant 11th or 12th century aspect when, after 300 years of development, it reached its current basic layout and inventory of buildings - it was in the 12th century that the English granted it the status of "Jurisdiction".

Perhaps "we" are being too blinkered in considering that a Cultural site must be "historic". Culture can be "as is" and still be worth preserving. By definition cultural landscapes represent the accretion of many years of human occupation.

Could there be a justification for having a (very) "few" non-numeric "Time Line" periods to cover situations which don't lend themselves to shoehorning sites into some century or other - that could include some cities covering a long and continuous period. I am reluctant to introduce what could be seen as a category of "Other" but feel that "Continuous" and "Contemporary" (my "not totally considered" first suggestions) do say more than "Other" does!

The worry might be that, as soon as we come across a site covering a number of periods, we just fall back on "Continuous" and "lose" the opportunity to highlight a significant element relating to a genuine period. A "purpose" of doing "Time Lines" is after all to highlight those sites which contain major structures/areas of development made at the same time as those of other sites. To merely describe Paris and and Prague as "Continuous" would lose the ability to link the Dating of Notre Dame for instance with contemporaneous structures. On the other hand most large cities will contain structures from a whole range of periods - should that make them all "continuous"? Preferably not - surely we can identify 2 (or 3?) periods which are at the heart of what makes "Paris -Banks of Seine" for instance. I guess we should just keep in mind the purpose of what we are doing - these matters are all "judgement calls" after all which should be made in the light of that objective.

We should also use the text feature to explain the choices made where they are not immediately obvious so that the logic is recorded for reference and reconsideration

Yeah, defining an "Other" category never is a good idea.

If we look at the Cultural Landscape category, I think it must be possible to date most of them to a specific age.

I also would not like to go into a "continuous" label for the major cities. They will always have had specific defining periods. In that case I'd rather use 2 or more age labels.

But then we're still left with the remaining ones, like Richtersveld. Even for that one I would like to pinpoint it to the start of the specific practice, or the date of the arrival of the ethnic group. Mainly because we use the start date also for the other age-related connections. And not only cultural landscapes are "continuous" , in a way major cities are too, as well as major (religious) monuments (think of rebuilding etc, like Kyoto).

Only in the case of Richtersveld it is not clear when it all started. There are written records on them from the 15th century, but they were there already earlier probably. Maybe I should just dig deeper on the internet on the history of the Nama people....

Re: Built in Prehistory
If we keep this connection we need to be more specific about it. Prehistory is technically defined as all ages predating the use of written records. In this sense the Inca Empire is prehistory. On the other hands much older sites such as the Biblical tells or Mycenae are historical in the sense they existed in a literary environment. This does not always overlap with the Stone/Bronze/Iron Age division.
Yet another problem is the meaning of 'built'. Ornated caves were not built of course but rather painted upon. Hominid remains are not even sites created by humans in any way. Should these be considered 'built in prehistory'?

I have been going through all the Chinese WHS and trying to date them. The Great Wall is a difficult one. First constructions of the wall start in the 5th century BC and go all the way to the 17th century AD (over 2000 years). However, little survives of the 5th century wall (and probably none if it is actually inscribed), futhermore China as a nation did not exist until the 3rd century BC so how can this be the Great Wall of China? There are two central dates that stand out the most to me. First, the major construction of the wall in a unified China in the 3rd century BC. Secondly, the Ming wall built in the 15th century. What we see today is primarily from the Ming dynasty and by far the longest sections. So I guess I would propose 2 dates for this exceptional WHS. Built in the 3rd Century BC and the 15th Century AD. What do any of you think?

Thanks for all the work!

If others would like to date some too, here's an overview of the WHS that have not yet a date yet: http://www.worldheritagesite.org/allage.php (the ones without a century between brackets behind their name)

Perhaps we should change the timeline for Mount Wutai. It's listed as built in the 20th century because of rebuilt sections by the communist party, however there are signifigant buildings from the Tang and Ming dynasties.

"It is seen as the global centre for Buddhist Manjusri worship. Its fifty-three monasteries, include the East Main Hall of Foguang Temple, with life size clay sculptures, the highest ranking timber building to survive from the Tang Dynasty, and the Ming Dynasty Shuxiang Temple with a huge complex of 500 'suspension' statues."

- Nomination File

For Dengfeng, Palaeolithic and Mesolithic was suggested. But I would go for 2nd AD: The nominated buildings were initially constructed over a span of eighteen centuries between 118 AD and the 20th century. The Tishi, Shaoshi and Qimu Gates have survived since Han times,

I agree, I removed it (or actually changed it to Contains significant 20th century structures)

I am wondering about the "transition" (going backwards in time) from "numeric centuries" to "periods" which we have so far adopted for "Timelines". The time line of "Prehistory" has quite rightly been abandoned but we still have Iron Age, Bronze Age etc.

Unfortunately these are somewhat imprecise and vary by continent/region in much the same way as "Prehistory" did. And, If we ever want to display time lines graphically, it would also prove problematical.

But to use divisions as small as "Centuries" that far back in history is not likely to be very helpful either. Carbon dating may well help achieve that level of accuracy (+/-!!) in many cases but the result could be spuriously accurate for our purpose. Things were just not changing that frequently to justify such a level of detail. Might it be better to use divisions at the century level of detail up to 10th Century BC (even that is possibly a bit too precice the earlier we go) but then to transit to 2nd Millenium BC (11th to 20th century BC) , 3rd Millenium BC etc thus keeping a numeric aspect??

I have just been looking at putting a time-line date on Mohenjo-daro. it was first built c2600 BC and abandoned c1800 BC. It could easily be assigned to "Bronze age" but such a title is largely specifying the technology in use rather than the "timeline" which can only be derived if one knows the dates of "Bronze Age" in the Indus Valley. For time-line purposes might it not be better to assign it to "3rd Millenium BC" which covers its major period of development?

This will of course still leave a "problem" with the tens of thousands of years and the millions - Pleistocene etc but i would suggest we just adopt larger numeric periods as necessary?

The "Technological Ages" could still be kept under the "History" group of connections -as, I guess, could "Prehistory"

I think Solivagant's idea is a very good one!

Concerning accuracy, it might just be necessary that some exceptional WHS have more than one "built in" timeline. (on a limited allowance) I think the Great Wall falls under this category, and some of the mixed sites around the world.

If this route was taken though, there would have to be limits, as countless sites have sites built in 2 or more different centuries. This would only work for specific exceptional sites that are near impossible to date to one century of primary signifigance.