Le Paso Jama is at 4,440m altitude. Suffice to say it gets really cold at night! But most people only pass through on their way to the Atacama Desert. It's a pleasant cross-border route if only just for a brief stopover. If you have your own car, you can stop for a picnic by one of the two lakes that are below the pass and home to flocks of pink flamingos.
The route is stunning - an endless landscape of ochres, yellows, browns, greens, blues set against a snowy, mountainous backdrop. Hardier travellers have been known to cycle along the pass; for my part, admiring the breathtaking view from the comfort of a car was perfect!
One piece of advice...make sure you fill up on petrol at the border. Although it may be more expensive than elsewhere, you'll have a hard time finding a petrol station along the pass. If needs be, you can head to one of the two border towns that sit on either side of the frontier.