Rádlo was founded at the beginning of the 15th century as a Czech village; the village was named Radlo already in 1419. In the place of the current Holy Trinity Church there used to be a chapel, dating back to 1725 - 1776.

The village is mainly interesting for tourists thanks to a nature trail going through the centre of the village. It leads through meadows with many protected plant species up to a small forest peat bog. Rádlo lies in the area between the northern part of Český ráj and southern part of Jizerské hory. Such a location offers visitors the possibility to set out on trips to both of these tourist districts.