What books with "doorways" to other worlds can you name?

[Kathryn]

In Charmed Life there are different dimensions - but not a whole lot of travel to them.

In The Ghosts the kids use some type of tea to travel.

[Nente]

Can't believe no one's mentioned H.G. Wells yet! The Door in the Wall is probably one of the earliest popular books like that.

[Justin]

Electric wrote: "You already mentioned The Chronicles of Narnia and the Phantom Tollbooth. I love those!
The Lost Years of Merlin he finds the world between earth and heaven. He got there on a raft, al..."

the lost years of Merlin was amazing, i don't think it gets enough recognition.

[Justin]

There is also A darker shade of Magic. There are certain people who can travel between 3 worlds by making "doors" link them.

[Rosa]

The Magic City
It's wonderful. All of E. Nesbit is wonderful.

[Gianna ⚔️]

The Fionavar Tapestry. The five protagonists are not children, but they are magically transported from modern Canada to Fionavar, the first world created and the most perfect.

[Justin]

Justin wrote: "Electric wrote: "You already mentioned The Chronicles of Narnia and the Phantom Tollbooth. I love those!
The Lost Years of Merlin he finds the world between earth and heaven. He got th..."

I third this, the lost years of merlin was absolutely fantastic, one many people haven't heard of.

[Rainbowheart]

William and Mary
The Door in the Closet

[SamSpayedPI]

The Beginning Place, although more NA than YA.

[Rosa]

Gates of the Universe

[Anne]

Some of Diana Wynne Jones books have already been mentioned, but in The Merlin Conspiracy, a boy travels between worlds on a goat.
In Interworld by Neil Gaiman, Joey has the ability to accidentally go to other worlds.

[Gillian]

This genre is sometimes called crossworlds fantasy!
The Twelve Kingdoms series by Fuyumi Ono - The Twelve Kingdoms: Sea of Shadow is the first book.
The Divide series by Elizabeth Kay - The Divide is the first book.
The Skinjacker series by Neal Shusterman - Everlost is the first book.

[A]

every heart a door, Mira Grant

[Ingo]

A wrote: "every heart a door, Mira Grant"
Did you mean this book? For the click, but longer title, different author.
Every Heart a Doorway

[Lobstergirl, au gratin]

Exit West but they're adults not children.

[Ryan]

Didn't see it mentioned but Coraline is where the girl finds an alternative world via little small door hidden in her new house.

The Magic Treehouse series, starting with Dinosaurs Before Dark, has the two kids go to different time periods, if that counts, via wishing on a picture in a book in the treehouse itself

[RU]

The Varayan Memoirs trilogy has portals between worlds done through doorways that are opened with magic signet rings. The portals are between the modern world and the fantasy one as well as different locations within the fantasy world.

First: Son of the Hero
Second: The Hero of Varay
Third: The Hero King

[Rainbowheart]

Firebrat
The Magic Within
The Late, Great Dick Hart
The Song From Somewhere Else

[Rainbowheart]

Dragonfly
My Own World
The Marked Girl
On All Hallow's Eve
Four Faces of the Moon

[Bella]

[Nicole]

Sorry for the excessively long list. I tend to get carried away when I browse my read-list for books with a specific trope.

The Key to Rondo The paintings on the music box Leo inherited from his great-aunt come to life when the music is playing. If you have the key, you can go into this world too.
Windblowne The MC travels to alternate universes on the end of a kite.
Princess Nevermore and its sequel have the MCs going from their underground magic/medieval kingdom into NYC (I believe).
The Clockwork Crow has the MC going to another world. Through a magic door in the locked room of the missing son of her guardian.
The Wishing Spell I’m embarrassed to say that I don’t remember how the MCs go to the different realm, but they do.
Steel she falls off a boat and into the past.
Story Thieves has one of the MCs able to jump in and out of books and she takes the other MC with her.
The Neverending Story one of the MCs saves a world by reading about it, then goes into the world.
Awakening MC gets sick and wakes up in the past.
Miss Peregrine's Home for Peculiar Children MC follows odd children and into a cave and comes out into a time loop.
House of Secrets The MCs move into a strange new house and it isn’t long until the house starts doing strange things and changing time/location.
Gregor the Overlander Described as Alice in Wonderland for a city kid. Gregor falls down a vent in his laundry room to a magical underground world.
A World Without Heroes Imagine falling into another world through a hippo’s mouth.
Into the Wild The MC doesn’t really go into another world. It’s more like another world comes out from under her bed and takes over her town.
Fable Weaver When people lie it tears the fabric between our world and the story world.
The Emerald Atlas Putting a photo in thee atlas will transport you to the time the picture was taken.
The Book of Story Beginnings Beware what you write in the book of story beginnings. You might end up beginning a story that you don’t know how will end.
Night of the Solstice When the MCs are asked to find the missing sorceress who guards their world from the fairy world, they must make a strange and complicated concoction so that they can walk through the mirrors in the house.
The Doomspell Trilogy The children are kidnapped and dragged through a magic portal by a witch.
Water Keep Two children connected across worlds by fate dream about one another. But when Marcus’s life is threatened, Kyja is able to pull him into her world.
Wings: A Fairy Tale Half-goblin Jak sent to kidnap strangely magical Tamisin from the human world, but when others come after her, Jak wants to protect her.
Into the Land of the Unicorns Cara and her grandmother spend their lives running from the strange men who pursue them. When the men get too close Cara’s grandmother gives Cara an amulet and directs she jump off the church bell tower.
Magic by the Book The MCs borrow a magic book from the library that has the power to bring them into worlds the king to visit.

[Cynthia]

do you like graphic novels? Locke & Key, Vol. 1: Welcome to Lovecraft by Joe Hill and Gabriel Rodríguez is about children and magic keys which take them to many different places--Netflix is currently streaming the TV adaptation--there are many books in the series, thrilling stuff and beautiful to look at

[Joanna G]

Also in graphic novels, SDCC DIE Volume 1 Fantasy Heartbreaker has D&D players going into their game land via dice. Dark, but great.

[Lobstergirl, au gratin]

Are you looking only for children going through portals? Juvenile books only?

In Salvation people travel through portals anywhere the portals exist, from one location on Earth to another, or between planets and galaxies.

[rory]

The Magic Half a young girl finds a single glasses lens in her room, when she looks through it she is transported through time to her own house with who would have been her sister in a different year
Seven Stories Up a young girl in an abandoned hotel tries on a vintage sleeping mask, when she wakes up she is transported through time to the same hotel with her grandmother (at the time her own age) in a different year
also I second Howl’s Moving Castle that book is amazing!

[Rainbowheart]

Tony and the Wonderful Door

[AngieA]

THE INVISIBLE LIBRARY (THE INVISIBLE LIBRARY #1) BY GENEVIEVE COGMAN

[Raymond Richard]

I’m trying to remember a book I read in the 1980s. The two kids go to another world. i think it was with magic rings but it wasn’t The Silver Chair. I’ve been trying to remember it for years. I think it was a boy and a girl and had a red cover. I graduated elementary school in 1986 so it must have been written in the 1960s-1986. Can anyone help me?

[Granada Dolores]

Coraline, The Cronicles of Narnia, Neverwhere

[Lobstergirl, au gratin]

Rick wrote: "I’m trying to remember a book I read in the 1980s. The two kids go to another world. i think it was with magic rings but it wasn’t The Silver Chair. I’ve been trying to remember it for years. I thi..."

Rick, start a new query in Unsolved. Don't piggyback on another thread.

[Ashley]

I don't think anyone's specifically mentioned that this is a well-known sub-genre of speculative fiction known as "Portal Fantasy." So if that's your jam, an internet search on that term will get you all sorts of suggestions in addition to the many here.

[Anh]

Inkheart and The Wishing Spell both traveled through books.