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Smallest you probably can't visit, then nothing for a very long way:

The smallest of the 8 Hawaiian Islands

To the West is a garden fit for the gods with very few things that decay.

Garden of the Gods (Keahiakawelo)

To the East is a needle that cannot be threaded and needs very few letters to say.

Iao Needle. Few letters with only vowels. This was my starting point. A quick search for "Needle Rock Formation" had Iao Needle at the top of the list. When I checked on it, the hint "Smallest of 8" fit perfectly into place. ^_^

They say outside where I came from, there are none larger.

Not quite sure on this, but a possible match is the Banyan Tree at Lahaina Banyan Court Park.

Edit: First post here. Just figured out spoilers. ^^"

My guess is that you are

The Nile River in Egypt (and other parts of Africa)

To the North I see headstones, but to my surprise - no grass, no dirt, and no clay.

The pyramids can be thought of as headstones, with Giza being near the northern part of the Nile. They are in the desert, no grass, dirt or clay.

To the South is the smallest you probably can't visit, then nothing for a very long way.

The source of the Nile (the White Nile by that point) is still not certain and there is jungle wilderness south of that

To the West is a garden fit for the gods with very few things that decay.

This may refer to the Valley of the Kings, where Kings were preserved and entombed

To the East is a needle that cannot be threaded and needs very few letters to say.

A needle is another name for an Obelisk and the Luxor (5 letters) Obelisk is east of the Nile in Luxor

They say outside where I came from, there are none larger.

The Nile is often called the largest river, though some sources say the Amazon may be.

Partial... I think you are

the Antarctic peninsula in Antarctica.

To the North I see headstones, but to my surprise - no grass, no dirt, and no clay.

This could be Deception Island just north of the peninsula, which has the largest cemetery on Antarctic territory.

To the South is the smallest you probably can't visit, then nothing for a very long way.

Perhaps the abandoned Chilean Arturo Parodi base, located just south of the peninsula. Apparently there are no bases between this and the Amundsen-Scott station on the South Pole.

To the West is a garden fit for the gods with very few things that decay.

This could be EDEN ISS, a greenhouse project on the Neumeyer III station, except that's to the east...?

To the East is a needle that cannot be threaded and needs very few letters to say.

No idea yet...

I think

you are a camel in the desert in the middle east somewhere, but I don't know why and I might be wrong... -- no grass, dirt or clay could mean sand... the needle that cannot be threaded reminds me of the quote 'passing a camel through the eye of the needle' -- sorry this is as far as I have got with it and don't understand everything and may just be wrong!

North:

Moloka'i's Veterans Cemetery is mostly catacomb style but above ground.

South:

From @El-Guest - This is Kaho’olawe, which is the smallest Hawaiian island and unpopulated. Further south of that is ocean for a long way.

East:

From @rin - Iao Needle, a mountain on the west coast of Maui.

West:

From @Rin - Garden of the Gods (Keahiakawelo)

I originally wanted to say you were referring to:

Mauna Loa which is the world's largest volcano by height and the largest above sea level by volume. However, this is on the big island which is to the east of all landmarks given.

I do believe that:

The landmark in question is on the island of Moloka'i due to the tight knit grouping of the other landmarks. Probably a volcano, or could be the surf in that area. However, the surf in Oahu is much larger than in Molaka'i.

You are:

The Buddha statue at Lahaina Jodo Mission, a Buddhist temple in Lahaina, HI (on the island of Maui)

To the North I see headstones, but to my surprise - no grass, no dirt, and no clay.

Just to the north is the Puupiha Cemetery, which according to a picture of Google Maps has headstones in sand (not grass, dirt, or clay).

To the South is the smallest you probably can't visit, then nothing for a very long way.

Going down south a little further is Kahoolawe, the smallest main volcanic island in Hawaii, which is closed off to tourism. And then just ocean until Antarctica.

To the West is a garden fit for the gods with very few things that decay.

Refers to the Garden of the Gods, which is on the island of Lanai, just west of Maui

To the East is a needle that cannot be threaded and needs very few letters to say.

Refers to the Iao Needle, a mountain east of Lahaina

They say outside where I came from, there are none larger.

The statue was brought in from Japan, and happens to be the largest Buddha statue outside of Japan.

And now to address the hints, many of which refer to the directions rather than the place itself:

Hint 1

If you go far from any location in Hawaii, you'll just see ocean.

Hint 2

"Iao" has very few letters and no consonants.

Hint 3

Kahoolawe is the smallest of the eight main volcanic islands of Hawaii.

Hint 4

"Zen" in "MetaZen" refers to Buddhism, and the location is a Buddhist temple.

Hint 5

Just to the north of the Lahaina Jodo Mission is the Puupiha Cemetery.

You are

The planet Jupiter

To the North I see headstones, but to my surprise - no grass, no dirt, and no clay.

Speculation of asteroid fields, no grass/dirt/clay on there

To the South is the smallest you probably can't visit, then nothing for a very long way.

The smallest of the eight planets is Mercury, you cant visit it since its way too close to the sun.

To the West is a garden fit for the gods with very few things that decay.

According to scientists Venus may have once been a garden planet, might also just be Earth

To the East is a needle that cannot be threaded and needs very few letters to say.

Saturn, threading the needle wouldn't quite work since threading the rings of saturn would mean going through the planet

They say outside where I came from, there are none larger. Where and what am I?

You're the largest planet, Jupiter

Hint #1

Before you go far in any direction, every direction starts looking the same.

.

Because of this the compass directions above are not relevant, planets rotate around the sun so at some point North will be South and vice-versa