Picton is the gateway to the South Island and the southern port for the ferry service that runs between the North Island and South Island.
The Marlborough Sounds surround Picton. They are an an intricate maze of waterways, land, and bush. A number of available tours by boat or plane are available but the Interislander ferry service takes you through much of the sounds and includes Tory channel and half of Queen Charlotte Sound. Other nearby sounds include Pelorus and Keneperu.
Once you arrive in Picton, you will notice that the town is small, but it caters well for tourists. It has numerous shops, cafes, restaurants, and good accomodation options. The nearby township of Waikawa, hosts one of the largest marinas in New Zealand and provides some great views of the sounds.
Activities are plenty. You can go swimming, sailing, fishing, scuba diving of the Mikhail Lermontov (the wreck of a Russian passenger cruise ship), bush walking (hiking), and just relaxing at one of many isolated inns located in the bush and on the waterfront. Not far from Picton is Blenheim which has some of the best vineyards in the country and offers wine tasting and restaurants.
Besides the many attractions of the area, Picton is also popular because it is a necessary destination for travellers exploring both islands by bike, car, or tour coach.