I have a feeling this record could easily be broken by taking a train through Europe, just have to figure out a route and spots to get on/off. Any suggestions?

Europe for sure, there has to be some route in Belgium or Netherlands that could collect 7+ world heritage sites, no? In Korea, I think you can do the 7 listed below in a day. The first four before noon, then hop on the KTX from Suwon to Gongju.

Seoul Metro Train
Changdeokgung Palace Complex
Jongmyo Shrine
Royal Joseon Tombs (Seolleung)
Namhansanseong

KTX (Gyeongbu/Honam)
Hwaseong Fortress
Baekje Historic Areas (Gongju)
Sansa, Buddhist Mountain Monasteries (Magoksa)

I think it is quite funny how he stresses the educational gain for his son when on this trip they could only touch each site before catching the next bus! But apart from this hypocrisy this seems quite a feat for Indian distances! Obviously public transport is much better in India then Inthought. I would also think this should be easy to top in Europe. I would also go for Belgium and the Netherlands. Els will know best. But also from London it should be doable?

Actually at the last WH meet up, Ivan and Nan have done research on it (starting from Brussels). I believe they came to 13 in 24 hours?

Fair play to them for going through with it and extra Kudos for doing it outside Europe.

I'm not sure I would really classify Taxis and Rickshaws as public transport, but still good work.

Not to do down their achievement, but just because it is the sort of person I am, my first thought was what was the quickest you could beat that score. I think you could visit 8 in under four hours if you focus on Brussels.

Start in WHS1: Flemish Beguinages namely Groot Begijnhof Leuven have a lovely walk through admire the architecture and after a further 19 minute stroll you could end up on Leuven's central Square gazing at the stunted tower of St Peter's church part of WHS 2 Belfries of Belgium and France.
-Walk or catch a bus to the train station 15 minutes away and jump on a regular train to Brussels Centraal, if you get the fast train it is only 22 minutes.
-When you arrive you can jump on the Metro to Montgomery station (16 minutes from Brussels Centraal plus 3 minutes for the next bit) , head above ground and walk to the second nearest tram stop which happens to be outside WHS3 Stoclet Palace,
-You can't visit the inside of the house so take in the exterior as you wait for a tram to take you 11 minutes to Oudergem-woud, the first stop inside Zoniënwoud/ Forêt de Soignes try to spot a beech tree in WHS4 Primeval Forests of Europe.
-Once that tree has been spotted retrace you tracks back to the Metro, getting off at Schuman for a short walk (tram metro and walk take 29 minutes) to Square Ambroix home of Hotel van Eetveld part of WHS5 Major Town Houses of Victor Horta.
-Again you can't see the interior so instead walk or get the bus (19 minutes) to WHS6 Grand Place (that is six World Heritage sites in just over two hours!).
Soak up the ambience with a waffle, before the short four minute walk back to Brussels Centraal station.
-Now you can sit back and relax on the train up to Antwerp Centraal, keep your eyes peeled for the huge belfry in Mechelen to complement the one you saw earlier in Leuven.
-On arrival in Antwerp admire the wonderful station whilst you get the metro/tram out to Antwerpen Olympiade where 1:15 minutes after being at your previous WHS you can see Maison Guiete part of WHS7 Architectural Work of Le Corbusier
-Again it isn't possible to visit so after a quick view, notice that it is next to the Antwerp Park and Ride so the bus can get you to Groenplaats in 16 minutes from where a three minute walk brings you to WHS8 Plantin Moretus Museum where you can enjoy a tour safe in teh knoweldge that you now hold a World Record!

Altogether the minimum time for this is (if you walk rather than run) is 3hr 37mins, with a fair wind and some robust scheduling you could comfortably beat the current record in 33% of the time, and all on scheduled public transport.

As quite a few of the sites interiors can't be visited, or are small and can be seen comfortably in a couple of minutes it isn't too different to actual proper visits of them.

So there is a base of 8 in four hours to start from, I think it would be reasonably easy to tack more on.
Heck I could even leave my office now and in five or so hours time start this having ticked off a further 4WHS in London (don't give me ideas!) that is 12 in say 10 hours not even starting from an optimal position, and not using any private transport.

Would I recommend this as the best way to visit Belgium's WHS? Nope
Would this be kind of fun to do if you have already seen them all? Yep
Is meltwaterfalls contemplating seeing if Mrs and Miss meltwaterfalls fancy a trip on Eurostar in the next few months? Perhaps :)

This record is no challenge. Can be easily beaten by one flight from Brussels to London.

Oh I've just notice this isn't quite right. It is in the buffer zone, however the inscribed zone is actually five very small parts of this forest. Will have a rejig, but I imagine it will add a bit more time to the Brussels leg.

Right so the rejigging would lead to.

From Palace Stoclet get a combination of buses to Watermaal-Bosvoorde, which is part of the core zone of the Primeval Beech Forests.
From there get a bus to Hotel Solvay, one of the other Major Town Houses of Victor Horta (32 minutes).
Then onward to the Grand Place by tram (22 minutes)

Altogether it adds an extra 42 minutes to the journey.

So altogether that is a minimum 4hrs 19 minutes, with the Brussels leg from Brussels Centraal through 4 WHS and back to Brussels Centraal accounting for 2 hrs 4 minutes.

I don't want to knock these guys for their achievement, but honestly I don't really see the point? Like the people who claim to visit every country in the world but then it turns out a bunch of places they just stepped over the border for a minute or two - what exactly are you learning or proving on a journey like that.

I see online that Indians are very proud of their World Heritage sites and justifiably so, so I guess kudos to this guy for showing his son as many of them as possible in a limited timeframe. But it just seems a little pointless I guess. At least they don't appear to be the usual publicity seekers trying to drum up business for their travel agency or whatever.

But they were!!
"The Guinness World Record title of 'most Unesco world heritage site visits in 12 hours by public transport' was bagged by the India-based Expeditions and Transcend Adventures firm. A total of 22 people were part of the record-breaking feat. The previous record was held by a duo in the Netherlands and was completed in 24 hours."
Mohammed Thahir, a 36-year-old IT professional in Abu Dhabi, wanted to partake in the world record feat with his five-year-old son, Mohammed Aayan, to teach him about perseverance and about the culture of their home country, India."
Pure publicity seekers (Don't you just "love" the bit about "My son also learned more about public transport"!!!!!) and a totally rubbish "record"

Here are the 2 Guiness WHS related records
a. 12 hours
http://www.guinnessworldrecords.com/world-records/526420-most-unesco-world-heritage-s ite-visits-in-12-hours
b. 24 Hours
http://www.guinnessworldrecords.com/world-records/373467-most-unesco-world-heritage-s ite-visits-in-24-hours

We discussed this latter about a year ago -
See - https://www.worldheritagesite.org/forums/index.php?action=vthread&forum=1&topic=2135# msg18116

and the publicity for the 12 hour "record" even gets it wrong that "The previous record was held by a duo in the Netherlands and was completed in 24 hours." - they are different "Records"!

You mean the Norwegian douchebag who wrote a book about it and now gets lots of perks? His tip for getting into Saudi Arabia is basically "have a press pass" *sigh*

P.s. flying from Brussels to London ain't public transportation :) I can imagine by car one could tick off up to 15 in one day by starting in Brussels. Most I've ever done was 4.

The person I was thinking of specifically was a younger woman, but I can't think of any particular details. I think her "visit" to Yemen was literally just getting turned back at the border /rolleyes

I vaguely know Johnny Ward (OneStep4Ward) and he took I think four different attempts to enter Yemen, eventually smuggling himself in on a supply ship to Socotra!

I watched the video of the 24 hours record. Quite entertaining but certainly not valid since they took several cabs. Cabs do not seem an acceptable means of public transportation. You could just as well hire a cab for the day or rent a car for the day!

I think there is a misunderstanding that the record requires public transportation, most likely because they did so in India and the newspaper picked up in that as a special achievement.