Not the most charming location, but placed in the middle of the main harbor run and with options for wade fishing and fishing from land.
The small island is located under the E20 highway bridge crossing over from Amager to Sjaelland south of the harbor. It's accessible walking or on bike. You can park on the Sjaelland side at the end of the road Stamholmen and walk or ride from there. Can be fished in most winds if it's not too windy.
Park on the west side of the bridge at the road Stamholmen and walk. Accessible by bike. No public transport.