The city
Samarkand was the jewel of the Silk Road, and it still looks the part. Come for Registan Square; stay for the necropolis, the mosques and the bazaar.
Two full days covers the main sights; three lets you add the observatory, the bazaar and a slower evening at Registan. Samarkand pairs naturally with Bukhara by train.
The Afrosiyob high-speed train from Tashkent takes roughly two hours; Bukhara is a further short train ride west. The old sights cluster together and are walkable; taxis are cheap for the observatory and outlying sites.
July highs average about 34 °C — sightsee early and late in summer. April–May and September–October are ideal. Registan and Shah-i-Zinda are busiest mid-morning; the light is best at sunrise and sunset.
Photo: Registan Square, Samarkand — Wikimedia Commons, CC BY-SA 2.0 fr, photo by Stomac.