I took a trip to the National Zoo last year and saw some stuff I hadn’t seen in a while (or maybe ever).
The Asia Trail I’ve seen many times over the last couple of years. But I don’t remember the last time I went into the Bird House. A lot of the birds were, of course, hard to get good shots of. But the Bird House has both indoor and outdoor flight exhibits that actually allow you to get very close to them, with no barrier in between.