In this guide, I explain how to find all the keys, Knowledge Books, and labels in Tidy Up History. I go through each room and explain where I find everything, so I can follow the locations without missing anything. There are spoilers ahead, so I keep that in mind before starting.
Key Locations
Theropod Room
I find the first key right on the map as soon as I enter the museum. This key opens the Theropod Room.

Ancient Egypt
I find the key to the Ancient Egyptian Room inside the Theropod Room.

Ancient Greece/Rome
I go up the stairs and look to the right when I reach the top. The key is sitting on top of a Knowledge Book.

Sub-Saharan Kingdoms
I go up the left side of the stairs. The key is sitting on the railing overlooking the center of the museum.

Andean and Mesoamerican Civilizations
I find this key on the floor in the Sub-Saharan Kingdoms Room.

Ancient Chinese
I find the key sitting on a box in the Ancient Egyptian Room.

Cerapod Clade
I find this key in the Ancient Chinese Room.

Mesopotamia
I find the key inside the Cerapod Clade Room, sitting on a display.

Ancient Japan/Korea
I find this key on the floor in the Mesopotamia Room.

The Stone Age
I find this key on the floor in the Ancient Japan/Korea Room.

Indigenous North America
I find this key inside the Stone Age Room.

Orthropods
I go to the Andean and Mesoamerican Room and look under the broken floorboards. The key is hidden underneath them.

Medieval Europe
I find this key on the floor in the Orthropod Room.

Non-Dinosaur Bones
I go to the Medieval Europe Room and look on a crate. The key is sitting there.

Ancient India
I find this key in the Other Fossils Room.

Islamic Key
I find this key on the floor in the Ancient India Room.

Knowledge Book Locations
Theropod
I enter the Theropod Room and look for a crate. The Knowledge Book is sitting on top of it and is easy to spot.

Ancient Egypt
I go up the stairs and find the Knowledge Book waiting in the middle.

Ancient Greece/Rome
I go up the stairs and look to the right when I reach the top.

Ancient Chinese
I find this Knowledge Book in the Ancient Greece/Rome Room.

Cerapoda Clade
I find this Knowledge Book in the Mesopotamia Room.

Mesopotamia
I find this Knowledge Book in the Mesopotamia Room.

Ancient Japan/Korea
I look on the floor in the Ancient Japan/Korea Room. It may also be sitting on a box.

Stone Age
I find this Knowledge Book on a crate in the Stone Age Room.

Andes and South American & Sub-Sahara
I go to the Andes Room and look for a crate. The Knowledge Book is sitting on or inside it.

Ornithopod
I enter the Ornithopod Room and look for the Knowledge Book trapped in webs.

Non-Dinosaur
I go to the Medieval Europe Room and look for a crate. The Knowledge Book is sitting on it.

India, Medieval and Islamic
I go to the Islamic Room and find all three Knowledge Books together in a pile.

Indigenous North America
I go to the North American Room and look in the upper-right corner. The Knowledge Book is hidden in some webs.

Label Locations
Ancient Chinese Room
I enter the Ancient Chinese Room and look inside one of the boxes.

Stairs
I find one of the labels on the stairs.

Ornithopod Room
I find one of the labels inside the Ornithopod Room.

Medieval Europe Room
I look for a crate in the Medieval Europe Room. The label is sitting on it.

Indian Room

I find one of the labels in the Indian Room.
Islamic Room

I look on the floor in the Islamic Room to find the last label.