We’ve been on a kick when it comes to historic townhouses, so why not finish off the week with one? Just across the Chelsea/West Village border is 237 West 15th Street, a century-old carriage house with a secret: A private courtyard separated from the street that leads to the building’s entrance. CORE’s Elizabeth Kee is marketing a one-bedroom apartment in the house, and her listing provides us with this excellent look at a lush and tranquil space that thousands of people walk by every day, yet few know exists.