There's the above mentioned Lapa Palace, a beautiful property and we have also enjoyed the Pestana Palace, a National Monument, fantastic grounds, rooms and service. Both properties are located in upscale residential areas. Both properties are most beautiful. Well worth the detour, slightly away from downtown. All two offer gardens, pools, Spas, restaurants, they feel all two like stately homes, but without being stuffy or pretentious. Overall, from our experience having stayed in both properties, they come highly recommended. Also all two are members of LHW. When not staying in Lisbon, but nearby, in the Sintra mountains we can also highly recommend the Penha Longa Resort, part of Ritz-Carlton, we stayed there recently as we wanted to be near the Lisbon coast and yes, it's a fabulous estate incl. historical buildings, golf courses and gorgeous grounds, also service was very welcoming, helpful and spot on. That's when you want to stay outside of Lisbon, but still within easy reach of Lisbon and the airport.