Lost River Caverns

{{Distinguish|Lost River Cave}}

{{Infobox cave

| name = Lost River Caverns

| other_name = Rentzeimer's Cave
Lost Cave

| photo = Lostriver1.JPG

| photo_caption = Lost River Caverns

| location = Hellertown, Pennsylvania, U.S.

| depth = {{convert|80|ft|abbr=on}}

| length = {{convert|1200|ft|abbr=on}}

| coords = {{Coord |40|34|51|N|75|19|51|W|type:landmark_region:US|display=inline,title}}

| survey =

| discovery = 1883

| geology = Limestone

| entrance_count = 1

| difficulty = easy

| hazards = occasionally rocks are slippery

| access = Fee

}}

Lost River Caverns is a natural limestone cavern located on the east side of Hellertown, Pennsylvania, United States, and consisting of five chambers. The caverns were formed by the karstification or dissolving of the limestone by water. In the past the caverns have been called Rentzheimer's Cave and Lost Cave.{{cite web |url= http://www.showcaves.com/english/usa/showcaves/LostRiver.html |title= Lost River Caverns |accessdate= 2007-07-14}} The "Lost River", so named because the source and mouth of the river have not yet been discovered, flows through it. The temperature in the cave is consistently close to {{convert|52|F|C}}. There is a gift shop and a museum before the entrance.

It was discovered in 1883 when a limestone quarry cut into it. It is open to the public.