During a quasi-business trip to Hong Kong in early November 2008 I managed to fit in a day's excursion to Mai Po marshes, a world-renowned site for shore birds.
Despite a) it not being the best month for birds, b) the tide being all wrong, and c) the weather being rather overcast for photography, I arrived at 08:00 and left around 17:00 so surprised myself with a nine-hour visit - and the time seemed to go very quickly indeed.
I saw 22 species of bird, 11 of which were new to me (bearing in mind I only started to get interested in birds a couple of months before). Not bad given the conditions, and my lack of experience in spotting the birds, and then identifying them...