Penthouse For Sell. Royal Castle is located at Sukhumvit 39 and only few minutes to BTS Phrom Phong station. Restaurants, Cafes, Convenient stores and shopping complex are in walking distance. This unit is penthouse type, 260 sqm, 5 bedrooms, 6 bathrooms, 1 maid room. If you’re interested, please contact us, Mon : 094-870-2288 / LINE ID: mon.c21.