Note: The following travel post includes special promotional content. Summertime is usually all about escaping the city and heading to the coast or into the mountains. But you don’t need to travel to have fun in the sun: There are plenty of summer activities right in Boston that will have you forgetting all about the heat and the crowds. From cooling off with a scoop of gourmet ice cream to singing “Sweet Caroline” (Fenway frank in hand, of course) at a Red Sox game, here are some great things to do in Boston.