You have no choice but to fly if you want to do a day trip to the capital Phnom Penh from Siem Reap, as a bus takes much of the day. And many travelers with flights in and out of Siem Reap have been known to pop down for a day. A morning flight there and evening flight back will give you around eight hours in the city and Cambodian Angkor Air offer promotional fares for as little as US$40 (plus tax) for the 45 minute flight. So you don't waste time, negotiate a day-rate with a taxi driver at the airport, or at the very least use the taxi to visit the Killing Fields at Choeung Ek, drop you back in town and then pick you up at the end of the day. See the sobering Tuol Sleng Genocide Museum, the glittering Royal Palace and the fascinating National Museum filled with Angkorian art and sculpture. Lunch on delicious Cambodian food at the training restaurant Romdeng in a lovely colonial villa, then take a tuk tuk to the stunning, yellow Central Market (Psar Thmey), above, to admire the Art Deco architecture as much as the fantastic array of street food, fresh produce, and souvenirs. For better quality arts, crafts, fashion, accessories, and art, take a tuk tuk to Street 178, known as Art Street, then stroll to parallel Street 240, a few blocks away, for more of the same, plus a handful of cool cafes and bars on Street 240 1/2. Wander down to the waterfront at Sisowath Quay to take in the late afternoon action and sip a cold beer from the FCC balcony before returning to Temple Town.