This lets you access the exterior parts of the building and gives you access to the rooftops. The hotel lobby has several suitcases with contents. You can find a Novice ammo Box and Explosives Crate on each of the two watchtower guard posts on the roof of the hotel
More containers in the west wing of the hotel:
In the outdoor pool, you'll find an industrial chest with the corpses of traders and settlers.
Active fusion generator with fusion core inside the wrecked ship below the rock cliff SW of the hotel.
The lobby inside the hotel doesn't contain much loot. The kitchen in the middle-north portion (consult your local map) of the second floor has an advanced wooden crate. If you head west through the hole on the wall, you can reach the two bedrooms blocked off by the debris in the corridor.
Make your way to the third floor. There's a hole on the wall to a bathroom that leads outside the island. Exit through the door and you'll reach the destroyed portion of the room with a wooden crate.