This contemporary apartment hotel is housed in a 20-story gray tower flanked by deciduous trees. It's on a side street that lends a quiet vibe to the place, creating the impression that it's much further from the bustling  main road nearby. The lobby is elegant and grand with recessed lighting, a crystal chandelier, and polished marble floors in neutral shades. Dark-wood tables and chairs and vases of flowers add to the elegant vibe. The 4th floor restaurant has a similar color scheme, but with a more casual ambience owing to wood paneling on the walls and more modern furniture. There's additional outdoor seating next to the pool, but that's about it for common areas. This hotel gets a mix of business and leisure travelers, and is notably popular with travelers from Japan.

This hotel is located on Soi 41 in Sukhumvit, a four-minute walk from the main road and a five-minute walk from the Phrom Phong BTS station (there's also a tuk-tuk shuttle for guests who don't want to walk). It's a busier neighborhood with tons of bars, mini-marts, and restaurants, plus massage parlors -- of all sorts. There aren't many tourist attractions in the immediate vicinity, and the Jim Thompson House is about a half-hour away by skytrain. Wat Arun and the Royal Palace both take around 30 to 40 minutes to get to by taxi. Both of the city's airports, Suvarnabhumi Airport and Don Mueang Airport, take 45 minutes to an hour to reach in low traffic, but can take much longer to access during rush hour.

This hotel offers five categories of room, ranging from entry-level Superior Studios to one-bedroom Grande Suites. Rooms are available on both smoking and non-smoking floors. Decor is contemporary, with medium-toned wood floors paired with a mix of dark-wood tables and light-wood and white cabinetry and trim, while abstract wall art and bed runners add color to the spaces. Many of the rooms have views of the Bangkok skyline, particularly those on the higher floors. Standard amenities include kitchenettes with full-sized fridges, microwaves, kettles, hobs, and washing machines, and cutlery, plus flat-screen TVs with DVD players, irons, and free Wi-Fi. Executive Suites have small balconies along with living rooms furnished with plush sofas and small tables, and even the Studios have nooks with dining tables that give them a separated feel. Bathrooms are big and light-filled, with walk-in showers in Superior Studios and shower/tub combos in most other categories. Grande and Executive Suites have separate walk-in showers and tubs. Toiletries and bathrobes are provided. Higher floors have excellent views of the city, and some rooms overlook the pool. 

Facilities are clustered together on the fourth floor and include a large fitness center with a great selection of cardio and weight-training equipment and big windows that look out on the hotel's small rectangular saltwater pool. Next to the pool are a few lounge chairs, plus chairs and tables for poolside dining from the hotel's adjacent Cafe Grande restaurant. A varied breakfast buffet with Thai and international items is served daily and is included in most room rates. A la carte items are available for lunch or room service delivery. Unfortunately, the restaurant isn't open for dinner. There's also a small meeting room that guests can use free of charge, plus an internet corner in the lobby and free hotel-wide Wi-Fi. There are four levels of parking for guests with cars and like many hotels in the area, Adelphi offers a free tuk-tuk shuttle to main road. Airport transfers are available for a fee.