Lonka? where do you get "Lonka?" Here's the unexplored lands list (in entirety)
Shrine of Chaos- FFI
Forbidden Land Eureka- FFIII
Pandemonium- FFII
Mirage Tower- FFI
Floating Castle- FFV
Matoya Cave- FFI
Crystal Tower- FFIV
Magic Continent- FFVI
Castle of Trials- FFI
Tower of babel- FFIV
Ronkan Ruins- FFV
Falgabird- FFIII
Magic Train- FFVI
Touzas Village- FFIII
Chocobo Forest- FFII,FFIV,FFVIII,FFIX
Semite Falls- FFII

Note: Due to the poor translation of FFT, some names may differ slightly.

Here are the treasures I've collected (incomplete list)
Adult's Bread- FFIII
Kid's bread- FFIII
Calcobrina- FFIV
Red/Black/Blue/White Materia- FFVII
Rat Tail- FFI
M Machinegun-FFVII
Minu Orb- Reference to character from FFII
Excalipar- FFV? FFVI?
Germonik Scriptures/ Zodiac Stones- FFT

The rest may not refer to a particular game that I am aware of.
Parasite Tree- ?
Longibunne Spear- ?
St. Elmo's Fire- ?
Tarot of Ben- ?
Magi-Sword- ?
M-Fiction Novel- ?
Diary of Nanai-?
Book of Enavia-?
Magical Gun- ?
Yurgeivogue- ?
Four Gods Set- ?
Statue of Lilys- ?
Beetle Charm- ?
Tobacco Pipe- ?
Zeni Sword- ?
Black Cat- ?
Malice Mask- ?
Parade Helmet- ?