Both anime and manga reveal that a Silver Millennium will exist in the 30th century centered in the city Crystal Tokyo.

Usagi and Mamoru will rule it under names of Neo-Queen Serenity and King Endymion,they have daughter named Princess Usagi Serenity.

The Earth becomes kingdom once again.

The Guardian Senshi protect the entire royal family.

However,the story makes no mention of the location of the Outer Senshi,other than Sailor Pluto.

After awakening in the manga,Sailor Quartet also act as guardians,but to Small Lady.

Luna,Artemis,and Diana live in the palace as well.

The Black Lady(but no other canon) show that the Outer Senshi are around during this time and help the Senshi of the present fight the Black Moon Clan.

At the center of the kingdom stands Crystal Palace,where the Royal Family and the Guardian Senshi live.

The manga depict over water,while in the anime it has another palace,Serenity Palace, located at the middle spire.

It is shown in the beginning credits for the second opening sequence of Sailor Moon R,is seen in a flashback where Chibusa thinks that Guardian Senshi and her parents.

Later,the interior is shown,indication that this is part of Crystal Palace where the Royal Family and their protectors live.

Exposure to the Silver Crystal renders all of the Earth's inhabitants functionally immortal.

Anyone not born in Crystal Tokyo becomes locked at current physical age,shown by the Queen,and King Endymion and the Guardian who appears as if aged in their early twenties.

Anyone born in Crystal Tokyo-Small Lady,for example is stated in the manga that to be 900 years old,yet has the body and mind of child.

According to her parents,such extremely slow growth is irregular,Chibiusa's childhood is important part of the fourth plot arc.

Though Serenity taken her place as Queen on Earth,Takeuchi leaves unclear whether she returns to the Moon as Neo-Queen Serenity re-establish as new monarch of the Moon Kingdom.

Although Crystal Tokyo was decimated thanks to the princess foolishly take her mother's crystal,Small Lady was not banished or sentenced to death for the thief.