Teh internets told me the best place to watch the bats was from under the bridge. So I crossed over to the south side and headed down to the water. There were plenty of folks waiting there. There was a bat expert sharing bat knowledge, including some darned useful information, e.g., when the bats had emerged the day before (not right at nightfall, but several minutes later; so giving up a few minutes after nightfall would have been a mistake).