If the wait is long for the Constitution -LRB- closed Monday -RRB- , check out the free museum -LRB- open daily -RRB- or go for a quick refreshment at Tavern on the Water , ( 617 ) 242-8040 , 1 Pier 6 , Charlestown , www.tavernonthewater.com , a few piers over , with one of the best restaurant views of Boston .