Czy moglibyście sprawdzić?

Czy ktoś mógłby sprawdzić mi (pod względem gramatycznym) krótką notatkę o Wielkim Kanionie?

The Grand Canyon is American's most beautiful natural landmark. It's one of the seven natural wonders in the world. It's 16km wide and 450km long. The Grand Canyon is made of red rock. Walls of Canyon were formed by water cutting through the rocks. This landmark was first time seen by Europeans. It's wonderful place to visit: you can go on hiking trips there, go camping or even see wild animals.

Wszystko dobrze - tylko to do poprawienia:
The walls of the Canyon were formed... This landmark was first seen by the Europeans (tu potrzeba kiedy? np w roku xxxx in the year xxxx)

Dokładnie tak powinno być :)
The Grand Canyon is American's most beautiful natural landmark. It's one of the seven natural wonders in the world. It's 16km wide and 450km long. The Grand Canyon is made of red rock. Walls of Canyon were formed by water cutting through the rocks. This landmark was first time seen by Europeans. It's wonderful place to visit: you can go on hiking trips there, go camping or even see wild animals.

Raczej tak powinno być, dzisiaj zdawałam egzamin więc wiem co i jak :
The Great Canyon is American the most beautiful natural benchmark. This is one from {about} seven natural wonders in the world. This is 16km wide and 450km long {debt}. The great Canyon is made from the red rock. Walls of the Canyon were {former} created water route cutting by rocks. This benchmark was the first time seen through of Europeans. This is the wonderful place that to be sometimes: you can go on the rambles of the travel there, you are going camping or even you see wild lives.

Sorry - nie zauwazylam poprzednio - America's.
A ta ostatnia wersja cos dla mnie nie wyglada poprawnie - ale jak Ty mowisz, ze jest dobrze to oczywiscie jest.

Dziekuję bardzo za sugestie, z tym że ta wersja użytkownika "wołów" raczej na pewno jest źle.