A travel telescope is a portable one with a further constraint: it has to survive a journey and fit in luggage. That pushes the design toward short tubes, small apertures and mounts that pack flat, and it changes what is worth buying.
What survives a journey
Sealed instruments travel best, which favours small refractors and maksutovs over open tube reflectors that arrive needing collimation. Carry optics as hand luggage where possible; the tripod and mount can go in the hold, since they are the parts that tolerate handling.
What fits in a bag
A 70mm to 80mm short refractor with a photographic tripod is the classic arrangement and weighs a couple of kilos. A 90mm to 127mm maksutov is heavier and gives far more magnification for planets. A tabletop dobsonian of 100mm packs surprisingly well if the base separates from the tube.
What a small aperture still shows
Under a genuinely dark sky, which is often the reason for the journey, a 70mm instrument shows a great deal: the Milky Way's star clouds, dozens of clusters, the brighter nebulae and every planet. Dark sky beats aperture for most deep sky objects, so a small telescope at a dark site outperforms a large one at home.
Camping and the practical details
A red torch, something to stand a tabletop instrument on, and a plan for dew. Away from home there is no kitchen table to improvise with, and a session that ends because the eyepiece fogged at midnight is a wasted journey rather than a wasted hour.
Questions people ask about telescope
What is the best travel telescope?
A short refractor of 70mm to 80mm for weight, or a maksutov of 90mm and up if planets are the target and the weight is acceptable.
Can I take a telescope on a plane?
Yes. Carry the optical tube as hand luggage and put the tripod and mount in the hold, where handling matters less.
Is a small telescope worth taking on holiday?
Under a dark sky, very much so. A dark site does more for faint objects than a large aperture does at home.