- “Stalagmite 17, the most escape proof prison in all of SlugTerra.”
- ―Mr. Saturday in the opening of Episode 30[src]

Stalagmite 17 is the most highly maximum security prison in SlugTerra.
Info[]
Stalagmite 17 first appeared in "Mission: Improbable", where Mr. Saturday took over and zombified the staff. After a fusion shot failed, Mr. Saturday captured and placed the Shane Gang in Stalagmite 17. Eventually this caused Burpy and Pronto to come and break the gang out, lifting the effects of the Cryptogrif Slug on the way.
In "Upgrade", the Shane Gang had transported the now captured Dr. Blakk to Stalagmite 17.
In "Back to Blakk" The Shane Gang, Millard Milford and the Security Slingers were helping Stalagmite 17 staff stop C.C., John Bull and Locke and Lode from breaking Dr. Blakk out of Stalagmite 17.
List of Inmates[]
- Mr. Saturday
- The Shane Gang (formerly)
- Dr. Blakk (formerly)
- Blite (possibly)
Appearances[]
- Mission: Improbable (First appearance)
- Upgrade
- Back to Blakk
- Dark as Night (Appears in flashback(s))
- Slugterra: Ghoul from Beyond (Appears in flashback(s))
Trivia[]
- Stalagmite 17 may be based off of Alcatraz prison.
- In Mission: Improbable, Trixie gets electrocuted when she tries to escape through the ventilation duct. This is a detail taken from the only successful escape from Alcatraz prison when 3 inmates successfully escaped through the ventilation duct in June 1962.
- At the end of the Judgement day chapter of Slug it out 1, Stalagmite 17 explodes for unknown reason
- The name of Stalagmite 17 is likely a direct reference to the 1953 film "Stalag 17" which takes place in a WW2 German prisoner of war camp.