Trier is located on the banks of the Moselle River. It is the oldest city in Germany, founded in or before 16 BC. It is pronounced Tree-ah.
The city lies in a valley between low vine-covered hills of ruddy sandstone in the state of Rhineland-Palatinate, near the border with Luxembourg and within the Mosel wine region.
Trier is the oldest seat of a Christian bishop north of the Alps.
Trier is known for its well-preserved Roman and medieval buildings, which include:
1)

The Porta Nigra constructed in 160-180 A.D.

It is the best preserved Roman city gate north of the Alps.

A view from inside Porta Nigra.

Yes. The city is old. According to the legendarium recorded in the 12th century, the city was founded by an eponymous, an Assyrian prince, placing the city's founding legend centuries before and independently of ancient Rome.
There is a medieval inscription on the facade of the Red House in the Trier market which reads,
- ANTE ROMAM TREVIRIS STETIT ANNIS MILLE TRECENTIS.
- PERSTET ET ÆTERNA PACE FRVATVR. AMEN.
Translation: "Thirteen hundred years before Rome, Trier stood / may it stand on and enjoy eternal peace, amen." This quotes reflects the proud city tradition.

These little Santas are looking at a building which I thought was the St. Matthias Benedictine Abbey. But, I think it is some other famous building, and I'm not sure which one.
If you know, please tell me what it is in the comments.
2)

The Trier Cathedral (Trierer Dom or Dom St. Peter)
This Roman Catholic Church is the oldest cathedral
in the country and dates back to Roman times. It is home to the Holy Tunic. This garment with a recorded history back to the 12th Century is said to be the robe Jesus was wearing when he died. It is only exhibited every few decades, at irregular intervals.
The edifice is notable for its extremely long life span
under multiple different eras each contributing some elements to its
design, including the center of the main chapel being made of Roman brick laid under the direction of Saint Helen,
resulting in a cathedral added on to gradually rather than rebuilt in
different eras. Its dimensions, 112.5 by 41 m, make it the largest
church structure in Trier.
3)

The Church of our Lady (Liebfrauenkirche)
This is one of the most important early Gothic cathedrals in Germany and falls into the architectural tradition of the French Gothic cathedrals.

This star is on the floor inside the church, and when you stand on it and turn 360 degrees...

. . . beautiful stained glass windows tell a story.
4)


Constantine Basilica
This massive structure, in the original Roman sense, was the 67 m (219.82 ft) long throne hall of Roman Emperor Constantine. Today it is used as a Protestant Church.
5)

The
Electoral Palace
This building sits directly next to the Basilika and is considered one of the
most beautiful rococo palaces in the world.

Concerts are performed in the Grand Chamber of the rococo wing
or summer open-air concerts in the courtyard. In both photos above, the Basilica can be seen looming behind the palace.
6)

Imperial Baths
Going to the baths was an important part of Roman life. Over 1600 years ago,
the Romans built one of the grandest and most impressive baths in the world: The
Imperial Baths. This was a gigantic bathing facility and descended into a subterranean labyrinth.

Men and women bathed naked, not always
separately, and could engage in sports, sit in cold and hot baths, swim,
get a massage, have their body hair removed by tweezers or wax, and be cleaned
with the help of scrapers, pumice stone, or fermented urine. Yup. You read that correctly. Fermented Urine. They could
relax, gamble, do business, go to the hairdresser's, libraries, reciting
rooms, or pubs.

And outside the entrance to the baths,we discovered Big Foot. Imagine giving this person a pedicure !
7)

Roman Amphitheater
Near the Imperial Baths are the ruins of a Roman amphitheater,
dating from the first century AD. The amphitheater was used in the
Roman imperial era (until the 5th century) for gladiator fights and
animal contests.

The person waving to you is is theHansMan. He is going to enter that 'rectangle' and visit the basement underneath the arena. This is where gladiators,
criminals, and exotic beasts were kept prior to their release into the
arena.
The entire structure, consisting of an elliptical arena and a
stepped auditorium, was surrounded by a high wall, divided into
individual stories by colonnaded arcades. The complex could seat up to
25,000 people.
In the 5th century, the inhabitants of Trier used the amphitheater
as a place of refuge from the increasingly frequent raids by Germanic
tribes. The site was used as a quarry in the Middle Ages.
Today, the amphitheater area is used for the Antiquity Festival and open-air concerts.

This is the basement. Good luck figuring out what you're looking at. I was more concerned with staying on the narrow wooden walkway and not falling into the water than taking photographs.
It was a bit creepy, and I just couldn't help but think what had gone on down here years ago.
AACCHHKK !
You have just visited seven of the most important sites in Trier.
And yes, in Trier there are . . .

Carousels and gluhwine . . .

Christmas pyramids . . .

Chocolate covered bananas . . .

Healthy food like this . . .

More gluhwine . . .

Tools made out of luscious chocolate . . .

Bouquets of fresh tulips . . .

Houses that look like this . . .
And then it was . . .

time to go home !