In the ancient Maya city of Caracol, map-making can be treacherous. Jungles shroud this site in the Central American nation of Belize. Dense shrubs stand taller than a person’s head. They hide ruins that otherwise would be obvious. To reveal the city, archeologists must hack through the growth, using sharp blades called machetes. They step carefully to avoid critters like the fer-de-lance, a common viper with an often-fatal bite.