Updated: Dec 14, 2020
This tank was on the street in Lima. No one paid any attention to it. There are lots of uniformed men around the city of various types, and I’ve seen at least one armed with what I took to be along the lines of an Uzi. Should I be worried? No. This is all normal here. Peru’s had several years of relative calm and the military/police presence is no longer a cause for alarm. However, you SHOULD check your country’s travel advisories prior to travel and be aware of current events, even if you’re traveling with ISA or another organization. This is not only a safety issue; it prepares you to carry on an enlightened conversation with the people of that country.
While we’re talking about unfamiliar sights: You may go into the bathroom where you are visiting and find fixtures strange enough you’re not sure how to use them. If you know you’ll be too shy to ask, search online for the customs (and fixtures) in the country you’ll be visiting. For example, there’s info on how to use a squat toilet at Lonely Planet.
This is the fixture where I’m staying. You rinse off with the sprayer, then the paper (which must go into the garbage because Lima sewers can’t handle it) is not so nasty. In Europe, I’ve also seen personal little towels for drying off. This is far cleaner than scraping oneself with paper, a habit many people consider bizarre and rather nasty.
Overall, the more you know about the places you’re going to visit, the more comfortable you’ll be.