Just north of the city and standing proudly atop a 660ft-high ridge, Fort Charlotte (1806) offers commanding views of both town and the Grenadines to the south. It was once a fearsome military post with dozens of cannon, a few of which remain. There are usually a couple of local guides hanging around who will show you around for EC$10 each. It's well worth contracting their services.
It's a stiff 40-minute walk uphill from town. Walk to the west end of Grenville St and keep following the road as it curves uphill. Like most roads in Vincy there's no footpath, so watch out for speeding vans. Alternatively, you can take a bus from the Leeward Bus Station to Edinboro and then walk the last 10 minutes to the fort.