In the main building. To the left of this is the counter for entry tickets, food and drinks and gifts as well as the stairs to the reptile and small mammal attic, and to the right is the door that leads to the zoo.
@KevinB I would estimate between 2 and 2,5 m wide and about 0,5 (small side) to 1 - 1,3 m wide on the longest side, can't be much bigger than that looking at the signs and surroundings. Both the arowana and stingray should have a tank multiple times larger than this (6 x 3 meters is a fair minimum in my opinion, and even that's not that big for fish that can grow to nearly a meter in size), and the oscar should also be housed a bit larger (a bit wider tank mostly, and a lot larger if kept with other species). The arowana might seem to fit now, but as is widely known under aquarists housing species in small tanks at young age has large consequences in the long term. Besides that arowanas are also quite active swimmers from time to time if given the space for it.