Naval Port of Karlskrona in Sweden.
This is an extensive World Heritage Site spreaded over a large area. It is located in Blekinge, the south east of Sweden.
This port was made newly in the glory days of Sweden. The harbor of the capital Stockholm was frozen in winter times so the Swedes needed a harbor that was free of ice all year round and closer to Denmark, the enemy in those days.
The choice was made for the archipelago of Karlskrona. The city was build with extensive naval buildings, e.g. the harbor itself, barracks, cranes, dry dock, rope factory, fortresses to defend the archipelago etc.
The see entrance of the harbor is defended by two fortresses, one of them featuring the round harbor, the other one is on the island of Aspo. During our visit we stayed in a stuga in this Island. It took several days to really explore this extensive site and to visit the several parts. Some parts are still in use by the armed forces and you will need to show your passport to get access to these parts.
Some of the must see parts in my opinion are:
the main square (Stortorget),
the churches Trefaldighetskyrkan (this holy trinity church resembles the Pantheon in Rome) and Amiralitetskyrkan (the admiralty church, the largest wooden church in Sweden).
The repslagerbanan (ropewalk), the longest wooden house in Sweden were the ropes for the naval ships have been made.
The Kungsholm Fort (the king's fort) with its round harbor
The Drottningkärs Kastell (the queen's fort) on the island of Aspo (opposite to the Kungholm Fort)
The ancient harbor Crane used to place a mast on the sailing ships
And although not a part of the WHS, do visit Brändaholm, a small island with all the houses in swedish red.