Lord Buddha advice on contemplation of man-made things Hundred years ago there were many natural beautiful things to observe and it was also easy to cultivate happiness. But in today's city life, we are surrounded by long buildings, roads, and traffics. We rarely spend our time with nature and are mostly surrounded by man-made things. Although breathing meditation can be done anywhere and this cultivates a lot of relief from our suffering, I was just wondering whether Lord Buddha had given any suggestion on the contemplation of manmade things to cultivate happiness/peace?
Is it possible to become peaceful by just contemplating on any man-made things and if yes then how?
OP: Is it possible to become peaceful by just contemplating on any man-made things and if yes then how?

You can meditate on kasinas. Please see the wikipedia page on kasina.
Technically, this is concentration on a man-made mental object.
I quote from it below.

Kasiṇa meditation is one of the most common types of samatha
meditation, intended to settle the mind of the practitioner and create
a foundation for further practices of meditation. In kasiṇa
meditation, a mental object (kasina) is used as the object of
meditation, being used to keep the mind focused whenever attention
drifts.
The meditation treatise the Visuddhimagga is centered around
kasina-meditation. According to American scholar monk Thanissaro
Bhikkhu, &quot;[t]he text then tries to fit all other meditation methods
into the mold of kasina practice, so that they too give rise to
countersigns, but even by its own admission, breath meditation does
not fit well into the mold.&quot; He argues that by emphasizing
kasina-meditation, the Visuddhimagga departs from the focus on dhyana
in the Pali Canon. Thanissaro Bhikkhu states this indicates that what
&quot;jhana means in the commentaries is something quite different from
what it means in the Canon.&quot;
There are ten kasiṇa described in the Visuddhimagga, which are also
mentioned in the Pali Tipitaka:

earth पठवी कसिण (Pali: paṭhavī kasiṇa, Sanskrit: pṛthivī kṛtsna)
water आपो कसिण (āpo kasiṇa, ap kṛtsna)
fire तेजो कसिण (tejo kasiṇa, tejas kṛtsna)
air, wind वायो कसिण (vāyo kasiṇa, vāyu kṛtsna)
blue, green नील कसिण (nīla kasiṇa, nīla kṛtsna)
yellow पीत कसिण (pīta kasiṇa, pīta kṛtsna)
red लोहित कसिण (lohita kasiṇa, lohita kṛtsna)
white ओदात कसिण (odāta kasiṇa, avadāta kṛtsna)
enclosed space, hole, aperture आकास कसिण (ākāsa kasiṇa, ākāśa kṛtsna)
consciousness विञ्ञाण कसिण (viññāṇa kasiṇa, vijñāna kṛtsna); in the Pali suttas and some other texts; bright light आलोक कसिण āloka
kasiṇa according to later sources, such as Buddhaghosa's
Visuddhimagga.

The kasiṇa are typically described as a colored disk, with the
particular color, properties, dimensions and medium often specified
according to the type of kasiṇa. The earth kasiṇa, for instance, is a
disk in a red-brown color formed by spreading earth or clay (or
another medium producing similar color and texture) on a screen of
canvas or another backing material.