There is a city in Germany named Kassel, but I don't know if proper nouns are counted when considering such a question.
A homophone for a speck is "spec". A homophone for "trench around a castle" could be "moat".
speck:motetrench around a castle:moat
The answer is that there is no homophone for can, but can is a homonym.
The homophone for "hymn" is "him."
the homophone for stationery is stationary
Your is a homophone of you're. In some dialects, yore is another homophone.
A homophone for "taut" is "taught".
A homophone for to is too or two.
A homophone for length is lenth.
A homophone for stock is stalk.
The homophone for "ale" is "ail."
The homophone is dense.