Day Trips
Hershey (~45 minutes)
Northwest of Lancaster, Hershey is built around the chocolate company that gives the town its name. It offers family attractions including a chocolate-themed visitor experience and an amusement park (confirm which attractions are open and current admission — needs verification). It's the more playful, kid-friendly option and works well as a full day out. See Hershey.
Gettysburg (~1 hour)
To the southwest, Gettysburg is the site of the pivotal 1863 Civil War battle. The national military park, visitor center, and battlefield drives make for a reflective, history-focused day (confirm current visitor-center hours and any tour fees — needs verification). See Gettysburg.
Reading (~40 minutes north)
In Berks County, Reading is a small former industrial city with an outsized list of sights: the hilltop The Reading Pagoda, the GoggleWorks Center for the Arts arts center, the Reading Public Museum & Neag Planetarium, and the walkable West Reading dining and brewery strip. A car is essential and the attractions are spread across a mountain and several boroughs, but it's a change of pace from the farm country. See Reading, Pennsylvania (source: reading-pa-research.md).
Fitting one into a four-night trip
With four nights based in Lancaster City, one full day works well for a single day trip — most travelers pick one of Hershey, Gettysburg, or Reading rather than trying to combine them. Choose by interest: families and chocolate lovers lean toward Hershey; history-minded travelers toward Gettysburg; arts, views, and a brewery scene point toward Reading. Drive times above are approximate (needs verification). The Four-Night Itinerary slots this day trip in as a choice.