There are a plethora of things to do in Cartagena - you have everything from sunset cruises and salsa classes to city bike tours and art tours! You can even take a day trip out into the Caribbean sea and experience the Rosario Islands.
There are some incredible hotels to stay at in Cartagena, whether you are looking for a budget friendly option or a luxury stay. My favorite area to stay is Getsemani, but there are tons of places around the city that won't disappoint!