This is how He who among us knows God best calls Him, Heavenly Father!
“This, then, is how you should pray:
“‘Our Father in heaven,
hallowed be your name,
your kingdom come,
your will be done,
on earth as it is in heaven.
Give us today our daily bread.
And forgive us our debts,
as we also have forgiven our debtors.
And lead us not into temptation,
but deliver us from the evil one.’
For if you forgive other people when they sin against you, your heavenly Father will also forgive you.
But if you do not forgive others their sins, your Father will not forgive your sins."
The Greek expression pater hemon en tois ouranois has "heavens" in plural as in Hebrew shamaim
Πάτερ ἡμῶν ὁ ἐν τοῖς οὐρανοῖς
Jesus has quite a lot to tell about our Father who is in heaven(s). In the teachings of the New Testament He certainly does not sound like a distant God somewhere there in outer space but someone who is surprisingly close to every human being in our most secret thoughts and prayers.
"But when you pray, go into your room, close the door
and pray to your Father, who is unseen. Then your Father, who sees what
is done in secret, will reward you. And when you pray, do not keep on babbling like pagans, for they think they will be heard because of their many words. Do not be like them, for your Father knows what you need before you ask him."
So where are these "heavens" if patriarch Jacob found that Heavens Gate in Bethel?
If the Father who is in heaven can hear your most secret prayer when you are all alone and knows exactly what you need?
Nicene Creed says simply that
Jesus suffered and was buried (Passus, et sepúltus est)
on the third day resurrected according to Scriptures (Et resurréxit tértia die, secúndum Scriptúras)
and rose up to heavens (Et ascéndit in cælum)
where He sat on the throne on the right side of His Father (sedet ad déxteram Patris).
From heavens He is coming back in glory (Et íterum ventúrus est cum glória)
to judge living and dead (Iudicáre vivos et mórtuos)
And His kingdom is eternal, has no end (Cuius regni non erit finis)
These thing expressed in faith and liturgy are no space trips as Juri Gagarin or Nikita were suggesting and many people think in their four-dimensional model of existence.
These heavens where Father and Son are sitting are not described with our everyday concept of reality down here, up there, or in astronomy terms that describe the physical space surrounding us who have not yet died nor been yet resurrected from death.