In which the protagonist or major character(s) are from the past (from our perspective) and travel even further into the past.

Example 1: A book written in the 1980s takes place partially in that time. The protagonist from that era finds themself in medieval Scotland.

Example 2: Our protagonist is from 1873. They somehow end up in the Mesozoic period.

Example 3: The hero lives in 1993 New Jersey, and is transported to 1975 New Jersey.

Not applicable: A character from the 1400s finds themselves in 1965. For books like that, check my other lists.

When adding a series, please add the first volume applicable to this list.