The 19th arrondissement doesn't have many tourist attractions, but locals flock to this hilly park, part of Napoléon III's "greening" of Paris (the emperor had spent years in exile in London and loved that city's public parks). Built on abandoned gypsum quarries and a former gallows, Haussmann managed to transform the mess into elegant apartments ringing a steep-sloped romantic escape; there are waterfalls, grottoes, mysterious pathways, a lake filled with swans, and even a pseudo-Greek temple. When downtown Paris is stifling, this is a nice retreat; there's even a Guignol de Paris (an open-air puppet theater) on the northern side of the park; shows start (weather permitting, closed in winter) at 3:30 PM Wednesday and weekends (EUR 2.50 charge).