Your shelter is your home on a mountain trip, and the choice between a tent, a bivvy bag and a hammock shapes how you travel: how much you carry, where you can stop and how you sleep. Each has loyal devotees and real drawbacks. This guide lays out the trade-offs so you can match the shelter to the trip.
Tents: the versatile all-rounder
A tent is the most forgiving shelter: full protection from rain, wind and insects, room to sit up, cook in the porch and wait out bad weather in something like comfort. Modern lightweight tents can be remarkably light, though truly storm-worthy models still carry meaningful weight. The costs are bulk, pitching time and the need for a reasonably flat, clear spot. For most mountain trips, especially with a partner or in unsettled weather, a tent remains the default choice.
Bivvy bags: fast and light
A bivvy bag is essentially a waterproof shell for you and your sleeping bag, cutting shelter weight to a minimum and letting you sleep almost anywhere: on ledges, in corners of huts or under the stars. The price is comfort: condensation can be severe, changing clothes is an exercise in contortion, and being pinned inside during a storm is claustrophobic. Bivvies suit experienced minimalists on fast, fair-weather objectives or as emergency shelter, not as a first mountain shelter.
Hammocks: comfort above the ground
A hammock with a tarp overhead offers arguably the most comfortable sleep in the mountains, cradling you off wet, rocky or sloping ground. On forested slopes where flat tent sites are rare, that freedom is a genuine advantage. But hammocks need sturdy trees, which rules out high, exposed terrain, and staying warm demands an underquilt or insulated pad beneath you, since cold air circulates below. In the right forest at the right season, they are superb; above the treeline, they are useless.
Matching shelter to the trip
Choose by terrain, weather and company. Exposed high routes and uncertain forecasts point to a tent; fast solo missions in settled weather suit a bivvy; forested low-to-mid mountain trails invite a hammock. Consider your experience honestly: a tent forgives mistakes that a bivvy punishes. Whatever you choose, practise pitching it at home before the mountains test it for you.
Tents protect, bivvies liberate and hammocks comfort, each at a price. Match the shelter to the ground you will sleep on, and the mountain nights will look after themselves.