People tend to check in during these times:
Turn off your mobile data or you might be charged swedish prices
Place is better on a warmer day
Awesome! Please come!
Bring a torchlight, if you're visiting for the casemates/cellars. You'll need it!
Best coffee at KulturVærftet just along the harbour
А теперь - дискотека...
Come in Summer. It was too cold in April
The best part of the tour is the one in the basements, but you totally need a light source. Flashlights are for sell at the beginning of the tour for a mere 20dkk.
Free audio tour in Danish and English if you can pick up the wifi or Bluetooth.
Read Hamlet before going.
The Copenhagen Card gets you in for free. Very cool to walk through the casements.
Careful when going down to the coast - the Swedish network is stronger than the Danish there, so you might incur roaming charges.
goes without saying - this is a must see - the old castle on the waterside of town.
Замок Гамлета, принца датского. Особенно впечатлили подземелья и бальный зал.
The inside is interesting to visit, especially the ballroom, but the best is the park and the castle view from the park.