The Blue Hill Observatory will undergo renovations for a year starting in June to preserve its National Historic Landmark Observatory Tower. Until late May or early June, the BHO is open for tours, either by appointment (7 days a week, 8:30AM-5:30PM) or walk-ins (Fridays through Mondays, 10AM-4PM). Discounts in the gift shop are aimed at reducing inventories of kites, books, educational toys and kits, weather instruments, geology items, and souvenirs including clothing, magnets, and mugs. And all are invited to celebrate Earth Day by climbing Great Blue Hill and stopping by the Observatory April 22-25 to be counted in the “Climb for Climate Challenge.”