While enroute to Ecuador from Colombia, I suggest that you make it a point to stop by briefly in Ipiales to view the Santuario de Las Lajas.
Firstly, if you take the early morning bus from Pasto, there is no need to stay overnight in Ipiales.
Once you arrive in Ipiales' large bus terminal, leave your luggage at the Left Luggage and walk outside to catch one of those urban buses to the city centre.
Once you sort-of feel that you have reached the city centre, get off and make your way to Carrera 6 and Calle 4. Please confirm this location with the locals whom you pass by.
From here, there are frequent shared taxis to Las Lajas that leave when there are 4 or 5 people.
As you walk down the gorge, you will see the backview of Santuraio de Las Lajas. You first see many many many plaques fixed on the side of the cliffs, expressing their utmost thanks, love and gratitude to the Virgin of Las Lajas who had presumably performed miracles for these families.
Turn the corner and be completely floored by the Gothic-style church and the dramatic location of the church.
Apparently, an image of Virgin of Las Lajas was painted on the side of the cliff. As a result, the altar is located here and the rest of the church is built JUTTING OUTWARDS from the cliff. Hence, this explains the location and the steep archways that lead down to the bottom of the ravine.
There is a tiny path opposite for you to take some good pictures DOWN at the church and there is also a path down to the bottom of the gorge for you to take pictures UP at the church.
Head back, have lunch and return to Ipiales' bus terminal. You will have time to cross the border to Ecuador and even arrive in Otavalo by 8 or 9pm.
What do you do when an image of the Virgin Mary appears on a cliff? Well, naturally you build a church on the spot!
It is said that in the mid 1700's that is exactly what happened, and in 1803 a chapel was build on the spot. Todays neo-gothic cathedral was built on the spot the Virgin is said to have appeared. There is a now a painted on version on the rocks where she is said to have appeared, this is inside the church.
These days people come from far and wide to say a prayer for a miracle and to put up a plaque of thanks if/when they beleive that prayer was 'answered'.
To get to Las Lajas cathedral, catch a bus along carrera 6, just ask which is the right one. The bus will leave you up the road from Las Lajas, from here just walk with the road down a ways. You should be able to see the cathedral in the valley to your right.
You must walk back up the road to this spot to catch the bus back, or just catch a taxi from the small village above the cathedral.
There are direct buses from Ipiales going as far north as Bogota. There are also frequent buses to Cali via Pasto and Popayan.
To cross into Ecuador, take a minibus to the border, cross the border then hop on a minibus to Tulcan, from where there are buses to Ibarra, Quito and elsewhere. The minibuses leaving Ipiales depart from the bus station or from calle 14 & carrera 10.
All around the cathedral you will see them. Along the cliff walls, on the stairs handrail, on the walls....everywhere. Thousands upon thousands of plaques of thanks to the 'Virgin of Las Lajas' for miracles performed.
These are plaques that individuals and organizations are putting up anywhere they can, in thanks. I looked at them for a while, reading them, but mostly just looking at the dates they were put there. The oldest ones are on the rock face above and to the right of the cathedral. The oldest I found dated back to 1946 and was put there by the minister of education.