The Brooklyn Botanical Garden is an urban oasis that sits close by in Prospect Heights, but gives you the sense that you've escaped the city entirely. Nature, as it happens, is also incredibly romantic.
The BBG's sprawling grounds contain enough to keep the two of you busy exploring for an entire day. From the Cranford Rose Garden to the Japanese Zen Pond teaming with coy, the solace that you misplaced in the city, you'll find here.
Explore their climate-controlled rooms (you can make it from rainforest to desert in just a few hours!) and marvel over their bonsai collection before heading off to the gift shop, where you can procure a tiny cactus to remind you of your day before heading off to the nearby Brooklyn Museum (200 Eastern Pkwy). If it happens to be a Saturday (hint, you should plan it that way), you can enjoy live music, beer and wine, and even take a dance lesson before heading off to scrutinize the latest exhibits.