As I enter Ukraine, the streets are dark.
It’s taken a day to get here and it feels surreal to finally be standing in a country at war.
Ten hours earlier I boarded a plane from London to Kraków in Poland. From there, it’s a three hour drive to the Ukraine border.
I’m here with a team of journalists from Newsround to find out how children are doing, a year after Russia’s invasion of Ukraine.
As we start our journey towards the border, it begins to snow.
Crossing into Ukraine is surprisingly straightforward. Our vehicle is parked up next to a white van painted with a Polish and Ukrainian flag. It’s carrying clothes, bottles of water and other essential supplies.
Every vehicle is checked. I hand over my documents and we wait.
Less than 15 minutes later, the engine is on and we’re on the move. The tyres of our car move forward slowly onto Ukrainian soil.
After months of planning, this is the moment I’ve been waiting for and my heart starts to beat faster.
Minutes later, the car stops. I step outside to record a quick video on my phone. The air is cold and it’s so quiet.
I take a look around but there’s not much to see in the dark.
We continue the drive to the city of Lviv in western Ukraine.
There are lots of houses set back from the main road. People are indoors, trying to stay warm – it’s bitterly cold outside.
There are no lights on, instead I can see candles flicker in windows as we drive past a row of houses. There’s a blackout, which means people in this part of the country are not getting electricity tonight.
The next morning, I’m up early and back in the car.
The journey to Kyiv, Ukraine’s capital city is seven hours long.
Just like the UK, there are petrol stations and fast food restaurants all along the motorway, but there’s something different that I’ve never seen before.
Buildings destroyed, apartment blocks badly damaged and warehouses burned to the ground.
It’s all evidence of a war, something I have never seen with my own eyes.
This war – the biggest in Europe since World War Two – is now a year old. A year since Russian president Vladimir Putin ordered his armies to invade Ukraine.
Last year, 13-year-old Viola had to escape her home in the middle of the night after her village was taken over by Russian soldiers.
“We didn’t even have time to look back at our house and we didn’t know where we were going,” she says.
Viola tells me how the Russian soldiers destroyed everything. “One night, we felt a huge explosion, it lit up my bedroom, shaking the house and waking us up.
“We kept running through other people’s gardens with the sound of bullets whistling near our feet.”
Viola, her younger sister and mum managed to escape and were evacuated to a safer part of Ukraine.
She invited me to take a look at where her house once stood. There are no bricks, doors or windows. A twisted pile of metal, some old pots and pans and charred wood is all that’s left.
The memories of what happened here are hard for Viola to relive, but like lots of the children I’ve met in Ukraine, she is determined to carry on with the things that make her happy, like playing the piano and spending time with her dog.
We kept running through other people’s gardens with the sound of bullets whistling near our feet.
Later that night, I return to our hotel in the centre of Kyiv. All the street lights are off so people carry torches to see where they’re going. Huge churches with golden domes are now shrouded in darkness.
Many families in Ukraine are living different lives now.
I’ve come to meet 11-year-old Dimitri. His town was also occupied by Russian soldiers.
When the fighting started, his family and their neighbours hid in garages on the edge of town, hoping they might be safer. They were wrong.
When the Russian shelling began, a young boy and his father in the garage next door were killed.
Dimitri’s apartment was also hit by a missile.
“I could never imagine that such a situation would happen,” he tells me. “I could never imagine that there would be a war and I could absolutely never imagine that my flat would be burned.”
Dimitri’s family had to find somewhere else to hide.
They made their way to a basement in a nearby pre-school building – where they stayed on and off for two months, sharing the space with 270 others. The conditions were difficult – food and clean water were limited.
He told me: “We spent a lot of time in the basement – it was cold and gloomy, of course we could see many people, parents, kids worried about their loved ones, of course we would hear the blasts that made us even more scared.”
I followed Dimitri down the steps to see the basement for myself. It smells damp and it’s very cold.
The community recently painted the walls in the basement to try to brighten up the place.
Dimitri tells me it looks so much better now. Last year, the basement had no electricity or internet.
We would hear the blasts that made us even more scared
Inside the basement, there are lots of rooms with small beds for children, toys to play with and bottles of water and food.
There are no windows, this is where people come when they hear air raid sirens.
Dimitri shows me the bed he slept in when he had to stay in the basement for weeks.
He said: “I’ve changed a lot during these past 12 months. I started to understand how good it is to have a home.”
Lots of children in Ukraine miss going to school.
Either ongoing fighting or school buildings being destroyed means online lessons only, and for others, even that’s impossible – there is no school of any sort.
I catch up with children who have just returned to the classroom in the city of Zhytomyr.
My camera operator picks up his camera and starts to record the children listening to their teacher.
Seconds later, the lesson is interrupted by a strange noise.
It’s an air raid siren, a sound that’s hard to describe and something I’ve never experienced before.
The loud warning rings out across the city and other parts of Ukraine to let the population know that an air raid is expected.
We begin to follow the children into the school basement where we stay for two hours.
I ask one of the boys how he feels. “I feel a bit scared and also a bit worried for my relatives and myself and for all my friends,” he says.
Underground, lessons continue and children dance and play games.
Teachers try to distract them from their worries – this is something they’re used to now.
The next morning, I’m woken up in my hotel room by the sound of another air raid siren. My phone goes off, messages from the team telling me to get down into the hotel’s basement as quickly as possible.
For the next four hours, we stay underground. The hotel’s car park has been turned into a shelter.
Over the course of the morning, Russia send a fresh wave of missiles over Ukraine. One lands less than 10 miles from our hotel causing damage to buildings and killing civilians.
The war leaves little opportunity for children to have a normal childhood and do all the things they enjoy.
I visited a group that has been set up to help them relax. It’s a place they can talk, play and create. Problems are put to one side, for a few hours at least, with a little help from Bise, a very energetic dog.
Sofia has been coming to these after-school groups and tells me: “Children will remember this war forever, some of them will have to take counselling for a long time, solving their problems.
“I think it shouldn’t have happened to the children.”
I leave Ukraine after more than a week travelling around, talking to children and I’m overwhelmed by their honesty and what they’ve endured.
I’ve also seen communities come together. They are protecting each other.
Nobody knows what the long-term impact on children will be – and nobody knows when this war is going to end.
But what is clear is that the children I’ve met, despite everything, have hope and a determination to carry on.
I leave Ukraine knowing that one day I will return.
You can watch the 30-minute documentary Ukraine: The Children’s Story on the BBC iPlayer.