Birjand Castle (قلعه بیرجند), 32.88288°, 59.20525°. It has got a pretty wowee look to it - big ramparts and turrets made of clay and brick. And then you can look down on the town from the top, and have a meal at the restaurant there. It dates from the Safavid era when the inhabitants were trying to fight off theTurks and Uzbekis. 2020-11-07
Kolah Farangi Citadel (ارگ کلاهفرنگی بیرجند), 32.87633°, 59.20808°. A palace built during the Qajar dynasty (i.e. 1789-1925) with some ziggurat features. Now the government buildings for South Khorasan so not much in the way of snooping around possible. 2020-11-07
Do
Buy
Bazar, Hakimnezari St, 32.88316°, 59.21306°. Covered marketplace with various stalls. Fruit, knick-knacks, etc. 2020-11-07
Eat
Shamso Alemare Traditional Restaurant (رستوران سنتی شمسالعماره), 32.85081°, 59.22826°, +98 56 3245 4220. 12ː00-15ː00, 19ː00-23ː00 daily. Try some Iranian standards here, looking out on an inner courtyard. 2020-11-07
Mountain Hotel (هتل کوهستان), 32.82724°, 59.18293°, +98 56 5832 3370. It looks like a major fortification. Not likely to miss it slapped up against a mountainside. Pool, gardens, restaurant, billiards. 2020-11-07