You may think such a holiday is a self-indulgent luxury, but the new research by Dr. Terri Orbuch at Oakland University in Michigan finds that taking an adult vacation is an essential part of great marriages.

Orbuch spent the last 22 years researching more than 350 married couples and found that couples who take time to get away together, and have unencumbered time (time when nothing is planned, nothing is programmed) have the strongest bonds. It is the single best thing you can do for your marriage.

In keeping with this new research, we’ve come up with the top nine of our most recommended adult-only destinations (from tame to spicy).

Jade Mountain, St. Lucia

Jade Mountain is a one-of-a-kind resort on the west side of St. Lucia, near Soufriere, the site of the World Heritage Piton Mountains. Partnered with its sister resort Anse Chastanet, we discovered that it’s all about beauty, nature, modern art and a blending of architecture into jaw-dropping scenery. All this with truly exceptional gourmet food and service, Jade Mountain propels relaxation to the highest level in an adult-only resort.

The rooms (or sanctuaries as they are called) are self-contained units that come with everything you need to relax (and no television, phone or radio). The sanctuary does have its own tranquil infinity pool in the three sided rooms which means you have the best of living both inside and outside for your entire stay.

It’s important to note that the sanctuaries are rectangular with no outside wall. That means open air in all the rooms, dining and common areas. It is a very different concept, and one of the few places in the world that has limited bugs, very few mountainous creepy or slithering things, warm weather, offers reasonable shelter from hurricanes and tropical storms and is relatively crime-free and difficult to access along the mountain-side. Think tropical camping with decadent comfort and push of a button service. The sanctuaries really do have to be seen to be believed.

As therapists, we’ve long believed that adventure leads to connection within a relationship. Anything that gets your adrenaline pumping together will bond you as a couple. One of the driving reasons to visit Jade Mountain is the duality it offers. At Jade Mountain there is the aforementioned complete tranquility of the sanctuaries, as well as the opportunity to take in couple adventures off the resort.

We went zip-lining, and during that tour had a quick lesson in the growing of bananas, bay leaves and cinnamon. We checked out the historic town of Soufriere. Other adventure couples took in the whale watching, rum tours, volcano hiking and ocean kayaking.