Connect with your spiritual side and offer up your own prayer at Church of St Pierre. Quietly reflect outside for a while or ask if you're allowed to join the next service.
You'll have sightseeing choices galore when staying in Aire-sur-la-Lys. Church of St Pierre is an ideal place to kick off here, but there are loads of other worthwhile sights to check out. Aire sur la Lys Town Hall, and Bailiwick are close to the house of prayer and and will cap off your day nicely.