1736 Massachusetts Ave, Cambridge.
Simon's is a Cambridge institution at this point. Walk in and you'll see the same old regulars lingering over the paper, plus a bunch of students doodling in notebooks.
It's not a welcoming space. It's like the longest galley kitchen you've ever seen. Narrow space, cramped tables...but eventually that all that adds to the charm.
The baristas are super friendly but of varying quality. In the mornings, you can get a shot pulled by Simon himself and he's usually on the top of his game. They have a decaf grinder, a grinder for the house (Barismo Clockwork) and then usually a Barismo single-origin, sometimes a guest espresso (often Terroir).
Ironically, I've never had the "coffee" at Simon's. The regular, batch-brewed drip. My friends say it's "weak" but I haven't verified. I spring for the espresso or, late in the afternoon (past 2pm), they do a pourover service with Hario V60s. About 12 oz for $3.75. They typically use Barismo or Terroir. Honestly, I can do a better job myself but it's nice to have someone else take care of it. They dose Barismo-style, so that 12oz. cup will usually have 27+ g of coffee. It's, um, strong.
Pastries aren't good. They do stock Taza chocolate, which is amazing, and serve some ok sandwiches and bagels.