Basically a monocular is half a binocular and is therefore half the weight and half the price..
Astronauts carried them on the Apollo missions. Mine is 8X magnification which is fine.

Mine is kinked in the middle because there's a prism in there, but you can get smaller un-kinked ones like these at about £10

Alternatively a cheap pocket telescope like this would do to let you know if the distant dots on a hillside are cattle or zombs-

NOTES:- Like I said, my monocular is 8x magnification which is fine, but if you buy anything more powerful (whether it's a monocular, binoculars or telescope) you run the risk of not being able to hold it steady enough to get a clear image.
At a guess, I'd say the problem begins to kick in around 15x, and by 35x it'll be much worse.
Also the higher the mag, the dimmer the image will be.
