I finally got round to making the BNW version. It ended up a little differently as I decided the gold bonus would be a bit boring.

+5 anything from a mid-game wonder seems really powerful, but I like it. Apply the bonus only once per city and you've got something awesome.

I'd like the wonder to somehow represent the silk road. There were in fact many trajectories, therefore the multiple city focus. I realise the usual focus on one strong city, but I always like wonders to promote different playstyles. Maybe I should add in some gold to alleviate the loss of gold from suboptimal routes: +2 gold, +2 science and +1 culture. That should provide sufficient incentive to spread out your routes? Also this would be added to the city's base yields, so +% modifiers apply.

It would work best for playstyles that emphasize internal trade routes, not external ones. External trade routes help with religion and gold and work best when they come from one central city (ex: Venice), especially with the East India Company. (Although I don't know how that particular National Wonder affects internal trade routes that all send food / production to a center city, so that wonder may be equally helpful.)
But I don't know enough about the IRL Registan to know if that's true to life.

How about: "+2 (or 1?) science and +1 culture in each city with a land trade route to or from a foreign city". The free observatory stays. Would encourage forming land trade routes (obviously), having many origin cities and building caravanseries in them. Would also set them apart from the many trade route enhancement buildings and wonders already in the game. A bit similar to Morocco's UA though.

Awesome! :D

I forgot about that, will give it a second thought!

Did you make a version that has trade route bonuses?

Compatible with BNW. I will do a version later though with trade route bonusses instead of the merchant gold, which are much more fitting.

no

does this have a 3d model

Now compatible with both vanilla and G+K.

You are correct.

I changed the icon to the madrasah one from the "Into the Renaissance" scenario, which is modeled on the same building. In the previous version I forgot to include one size (the one shown upon completion), but that's fixed now.

I like it: unique benefit to help civs using merchant specialist and, if I read right, a way to get an obvervatory via wonder if not by a mountain.

Definite subsription.

Much needed financial relief.

Monument from my country! thanks