The Altis Belem Hotel & Spa is a 50-room boutique in Belem, a residential neighborhood on the Tagus River. Belem is slightly removed from the city center, but has several of its own attractions, as well as gorgeous marina views and lovely restaurants lining the river. The hotel's rooms are sexy and spacious, with white decor accented by green rugs and unusual wall murals. Marble bathrooms are open -- with little privacy -- and some have inviting soaking tubs. Some rooms also have balconies with marina views and private whirlpools. Despite its small size, this hotel has many amenities, including a spa, a big indoor pool, a fitness center, and a Michelin-rated restaurant. Guests that want to be within walking distance of more attractions might consider the Altis Avenida, also a boutique hotel, with modern rooms in the city center.