Hiking Ymittos mountain (Greece)

What more can I ask for as I take my car for a 40km ride up to my next hiking destination? It's a truly perfect September day with weather conditions beyond ideal. Check out previous posts of mine to get and idea weather wise. The only obstacle I find on my way is at the last km of a gravel road where this turtle decides to have her morning walk right in the middle:

I mean the perfect middle:

My car is tall enough for her but I didn't wanna scare or even worse risk it so I stopped to put her aside. Besides, next driver could hardly be more careful than I am so...Here she is after her safe transfer staring at me like "why did you do this to me?"

I park the car under the poor shade of a semi bare tree and the place already intrigues me to start exploring/hiking:

My first goal is to see the entrance of a tunnel that was left unfinished in the 80s. It would connect Athens with the East towns of the region but the project was abandoned. As I make my first steps North West I see the first signs of it on the left side of the road:

Steps later I am in front of the entrance and make a few steps inside it:

Sorry but I didn't walk further in this stinky thing full of insects. It's 175m long ending at a cave. Probably they stopped because of the cave and maybe this was one of the reasons the project was abandoned. Hard to say for sure though as it's also hard to find info about why they dropped it.

Things are brighter and more attractive under the sun so I move on:

I have the option to follow the road that connects the local huge pillars for the power cables:

Instead I decide to follow the hikers path. It's harder but more scenic plus part of it is under the shade of the trees which is very welcome on a warm sunny day.
Soon enough the view rewards me:

And the path itself is nice too:

With lots of signs for hikers on the way:

Not that we need them that much anymore (nothing's secret after Google) but it's nice to see them.

The path stays nice all the way:

To my surprise I later find this piece of concrete on my way:

Knowing the length of the tunnel I am almost sure that this was supposed to be its ventilation hence those pieces of wood roughly put on top to prevent a soul from falling in.

I leave it behind and follow the path:

The view often makes me stop for some pictures:

I follow the path and those cute signs,

which lead me to this rock where I get a sense there's must be something nice on its top there at 500m above sea level:

And there is indeed. A small plateau with nice view to both sides of the mountain:

This used to be the way people followed to go to Athens and back to the East side of the region from the ancient years even up to the 1950s as this is the lowest pass of this 1000m high mountain.

I still have way to go so I continue West:

It takes only a couple of minutes to stop again for this stunning view:

I can't say no to tiny flowers like this:

While a young flower is born, a tree lies dead overlooked by the rock:

Since you already saw the view to the East side of the region a couple of images ago it's time to have a look to the West now:

This spot offers fantastic view to both sides so here's one more from the East:

Can it get any better? Hard but maybe with a little help from this tiny cute flower:

Steps later I can't resist one more shot looking West:

FYI, the signs of civilisation you see in the background are the South East suburbs of Athens.
I follow the path heading West,

but it's hard to say no to the view on my right:

Vegetation gets more dense as I continue:

I find this window in the woods for one more shot:

One more tree lies dead among its comrades:

My final goal is to reach an open top cave but before I reach it to my surprise I see this one instead:

I deviate to get closer and I'm instantly stunned by this rock full of holes looking like Swiss cheese:

Pure rock art by nature isn't it? Pure shit act by humans at the same spot isn't this?: