Where the canal leaves the capital
Tongzhou is the northern end of the Beijing–Hangzhou canal. The listed waterway goes on for more than 2,000 kilometres.
Tongzhou.
The municipal page places Tongzhou in Beijing’s southeast and calls it the northern end of the Beijing–Hangzhou Grand Canal. The World Heritage canal is a serial waterway from Beijing to Zhejiang. Tongzhou is where that northern sentence becomes a district, not the whole canal.