It’s the end of your day. After two freakishly long meetings, a session of elbow-throwing over round-toe platforms, and an onslaught of lost tourists. You need to take a load off and turn it waayyy down. Destination: the new Westin Waterfront. Settle yourself in its sprawling lounge, Birch Bar, and you immediately get the picture. A Zen-like trance washes over. You’re consumed by the elemental. Observe. Earth: wide-slab wood floors, towering birch trees, a long granite bar, and a massive stone wall at the lobby’s end. Water: easy-drinking signature cocktails like the White Birch (vanilla vodka, honey, and white cranberry juice). Fire: a menu of grill staples with a twist, like mini burgers and skewered chicken lollipops. Air: piped-in aromatherapy that instantly sets your mood to chill. In your newfound state of bliss, you’re ready to take on the world. The map-wielding tourists, however, are definitely on their own. Birch Bar, at the Westin Waterfront Hotel, 425 Summer Street (617-532-4600).