The Charlesmark occupies a convenient location that’s now tinged with tragedy: overlooking the Boston Marathon finish line. The six-story building, erected in 1892, predates the race, and its conversion into a budget-boutique hotel created a worthy competitor for this neighborhood’s many large chains. Guest rooms are small but have pillow-top mattresses and mini-fridges. They feel like ship cabins, with built-ins that help alleviate the space crunch. The included breakfast makes this place a bargain, but note that there’s only one elevator.