Alltwalis is situated along the A485, at the bottom of the hill that gave the village its name: Yr Allt Walis (Allt means a wooded slope). Economic activities in the village are mostly agricultural with sheep and dairy farming. Many of the inhabitants of Alltwalis work in the nearby town of Carmarthen.
The centre of the village is dominated by the Chapel (now closed) which was built in 1897 to replace an older chapel. Next to the Chapel is The Mason’s Arms, a friendly rural pub. Opposite the Chapel and the pub is the School. It was built in 1881 and was the community primary school until Summer 2003.
Another dominating building along the main road is Yr Hen Tollborth (The Old Tollhouse)which was built in the middle of the 19th century. From here tolls were collected from travellers and merchants who were on their way to the old market town of Carmarthen. Just south of the tollgate is a complex of three residential homes. These homes comprise the building that used to be a woollen mill, called ‘The Factory’. This mill was also built in the middle of the 19th century and conveniently placed at the Carmarthen side of the tollgate so that no tolls would need to be paid there.