Nature Reserves

A friend asked me the other day what was the best nature reserve I've ever been to. This really got me thinking, there's so many to choose from. In the UK it probably is Ynys Hir RSPB on the west coast of Wales particularly in early May. Even when we've not seen much we've always come away refreshed. Abroad it's a small reserve in Germany, between Regensburg and Deggendorf, at Isamunde, although the Aquamolls in Spain runs it a close second.

What's yours and why?