@Hvedekorn I thinking about a city trip to a northeastern European capital (Riga, Tallin or Stockholm). A good zoo is an important condition. Would you recommend Riga Zoo? When I see all your photos of the Tropical house, that part of the zoo seems to be a good reason to visit Riga Zoo.
If you would like to see the city of Riga itself, then yes, the zoo would be a fine addition to a very nice city. If you're travelling only for the zoo's sake, probably no. The tropical house is indeed very nice and very cleverly designed (it's actually not very big, but it feels big and fits in lot of animals due to the having several smaller corridors on different levels), and I'd say it's the highlight of the zoo, but many of the other exhibits are not too inspiring, in a few cases downright bad (hippos, polar bears, some of the older aviaries). The collection is fairly good, but not out-of-the-ordinary-good. Furthermore, it's not a very big zoo, though you can spend half a day there if you want.
Since zoo visits are important to you, I'd suggest you go for Tallinn. Tallinn Zoo seems (I haven't been there) to be a bit better than Riga Zoo now that they don't have their horrific polar bear enclosure anymore, and it's certainly larger. Stockholm doesn't have a "proper zoo", though it does have a Nordic animal zone at the Skansen open-air museum and various smaller aquaria. I mostly chose Riga over Tallinn because none of my nearest airports had direct flights to Tallinn.
