The town of Machynlleth, with its prominent town clock built by the Londonderry family in the late 19th century, is just a 5 minute drive down the hill from the cottage. Machynlleth is an ancient market town which is renowned as the site of the first Welsh Parliament. The Owain Glyndwr Centre, a small museum and historical exhibition, is built on the site of this Parliament.
Even if you just visit town to provision for your stay (there is a good Co-Op at the end of the high street, and a Spar on the high street, for this purpose), it is worth spending some time in Machynlleth to wander round. There are a range of shops in town, including a host of antique shops (where you can pick up a bargain if you're lucky!), textile shops and gift shops. You can pick up your morning paper from Mr News behind the clock, meat from Will Lloyd Williams (a family business running the last small independent abbatoir in Montgomeryshire), bread from the local bakery and there is also a pharmacy should you need one during your stay.
There are several cafes in town, including The Quarry Cafe, a vegetarian cafe focused on sustainability, and Number Twenty One, which has recently opened and is focused on using locally sourced Welsh ingredients.
Machynlleth hosts a market day on Wednesday mornings, which is worth a visit, though it is good to go early.