Thunder Bay, formerly the twin cities of Fort William and Port Arthur, is a city in and the seat of Thunder Bay District, Ontario, Canada. It is the most populous municipality in Northwestern Ontario, and the second most populous in Northern Ontario after Greater Sudbury. The census metropolitan area of Thunder Bay has a population of 122,907, and consists of the city of Thunder Bay, the municipalities of Oliver Paipoonge and Neebing, the townships of Shuniah, Conmee, O'Connor and Gillies and the Fort William First Nation. The city takes its name from the immense bay at the head of Lake Superior, known on 18th century French maps as "Baie du Tonnerre". The city is often referred to as the Lakehead or Canadian Lakehead because of its location at the end of Great Lakes navigation.

Thunder Bay's main tourist attraction is Fort William Historical Park, a reconstruction of the North West Company's Fort William fur trade post as it was in 1815, which attracts 100,000 visitors annually. The marina in downtown Port Arthur, an area known as The Heart of the Harbour, draws visitors for its panoramic view of the Sleeping Giant and the presence of various water craft. The marina also includes a lake walk, playground, harbour cruises, a children's museum, and a Chinese/Canadian restaurant. There are several small surface amethyst mines in the area, some of which allow visitors to search for their own crystals. A 2.74m (9 ft) statue of Terry Fox is situated at the Terry Fox Memorial and Lookout on the outskirts of the city near the place where he was forced to abandon his run.

Wikipedia articles for Thunder Bay

• Thunder Bay (Ontario landform)
• Lake Superior