St. Catharines is the largest city in the Niagara region of Ontario, sitting on the shore of Lake Ontario at the northern end of the Welland Canal. Most travellers pass through on their way to Niagara Falls, but the city makes a decent base for exploring the wider peninsula.
The Welland Canal itself is worth a stop — the St. Catharines Museum and Lock 3 viewing platform let you watch enormous lake freighters rise and fall through the locks. The surrounding Niagara wine country, with its concentration of icewine producers, is within easy reach. Port Dalhousie has a historic harbour, beach, and 1898 carousel; downtown clusters around the renewed FirstOntario Performing Arts Centre and the Frederick Olmsted-designed Montebello Park.