I thought so as well, but I did see the door open to their outdoor enclosure in August 2017! Didn't see any of the animals outdoors, but one of them was lying in the door between the indoor and outdoor enclosure. My guess is that the door is closed most of the time, but opened on days with very good weather? I was also under the impression that they no longer had access outdoors, so was very surprised to see the door opened last year.
Belgrade zoo keeps Cuban crocodiles and American alligator outside during summer. They kept White-throated monitors and Green iguana outside also… and there is a pool full of Red-eared sliders - ex pets.
Another species I've found in the gallery that has been kept outdoors in European zoos is the spectacled caiman, at Jászberény Zoo in Hungary. This zoo also has an outdoor enclosure for Burmese pythons (as shown in the picture below). Burmese rock python outdoor enclosure @ Jászberény Zoo, Hungary - ZooChat
Borth Zoo used to have outside access for their Spectacled Caimans, which bred. Thrigby have outside acces for their American Alligators.
London Zoo has Galapagos giant tortoises in an outdoor enclosure and had a Chinese alligator in the old penguin pool.
La ferme de crocodiles in Pierelatte (France) keeps at least three non-European species outside: Nile crocodiles, Chinese alligator (no visible indoor enclosure) and African spurred tortoises.
I think that enclosure was originally used for a fairly large American alligator. I don't know if London or Chester still let their Komodo dragons sun themselves in their outdoor enclosures. I did once see the old crocodile monitor outside at Chester in 2014. I also remember seeing a rhino iguana in the old beaver pen at Regent's Park on a warm summer day perhaps 20 years ago (the site of that old pen is now part of the lemur walk-through).
Bristol Zoo have their rhino iguana in an outdoor/indoor yard (just as an example). Pierelatte - Chinese crocodile species in outdoor as temperate species (with hibernation preferably in an outdoor enclosure).
Artis in Amsterdam also allows their rhino iguana together with their Aldabra giant tortoises outside, and Blijdorp and Duisburg have respectively Galapagos and Aldabra giant tortoises with outdoor exhibits. I guess the Australian water dragons comes from Pairi Daiza? Because they are no longer kept outside since a couple of years (even out of the collection I think).
I think I have seen them once on the lawn a couple years back (2015 or something like that). I did forget however that the outdoor enclosure is also gone now, and I'm not sure wether it is planned to return or not.
Noah's Ark Zoo have a large outdoor enclosure for their Aldabra tortoises. Budapest have (had?) an outdoor enclosure for crocodilians.
I thought it was destroyed in favor of the lemur enclosure, but I guess that will be in the next fase of "Eiland-hoppen" then.
At the moment, there is still an outside part of the enclosure for the Galapagos giant tortoises at the Rotterdam Zoo (Blijdorp). Although they rarely use it by them. I only saw it used ones, last year. The part of the "Eiland-Hoppen" project will be realised upon its place.
I was just looking around this morning and found an interesting post about the outdoor reptiliary at London Zoo - as mentioned, it seems to have been essentially a mix of European and British species with only one exception that I could notice. A guide from 1935 lists the following species (I will include the old taxonomic names here): Great green lizard, Lacerta viridis major - I think a synonym for the Balkan green lizard, Lacerta trilineata Green lizard, Lacerta viridis Glass snake, Ophisaurus apodus Eyed lizard, Lacerta lepida Wall lizard, Lacerta muralis Grass snake, Natrix natrix Aesculapian snake, Elaphe longissima 'Dark green snake', Coluber gemonensis Northern viper, Vipera berus European pond turtle, Emys orbicularis Spanish terrapin, Clemmys leprosa Painted terrapin, Chrysemys picta Edible frog, Rana esculenta Common frog, Rana temporaria Several species of newt Other sources also mention slow worms, smooth snakes and a big dark green snake that is possibly the green whip snake, Hierophis viridiflavus. The open-topped display did have many problems, especially with predation. In one incident, all the small lizards were eaten by a flock of cattle egrets that the zoo allowed to fly freely while in at least one case a domestic cat jumped into the enclosure (in this case it was attacked by the large dark green snake and had to be retrieved). Several other British zoos had similar reptiliaries for native reptiles - mentioned are Bristol, Edinburgh, Whipsnade and Dudley (the latter apparently might still survive, as the listed enclosure now used for meerkats). More information, including photographs of the London Zoo reptiliary, comes from this link: The Outdoor Reptiliary in Britain. 1. London and Other Zoos
