In the west, Rotterdam
The Kiel Canal links the North Sea with the Baltic.
Washington D.C.
San Jose, Costa Rica, is the capital of the North American nation other than Panama that is closest to the Panama Canal.
Beijing in the north and Hangzhou in the south.
San Jose,Costa Rica
If you consider Panama to be a North American country. (Since the canal runs through it, the country is divide between the north part of the country which is in North American and the southern part which is in South America.) If Panama is considered, the answer is Panama City, Panama. If not, the closest exclusively North American capital is San Jose, Costa Rica.
Costa Rica
The Erie Canal connected the Hudson River at Albany with Lake Erie.
The Erie Canal connected Albany with Lake Erie at Buffalo.
The Erie Canal connected Albany with Lake Erie at Buffalo.
Please rephrase - the question is unclear.