Gravel and soil mess

[Soul31]

Hi I am totally clueless with gardening so am hoping for some help with this please, there is a largish sunken round section at the end of my garden that appears to be full of soil and gravel all mixed together. The level of it is lower than my grass so even though ideally I’d like to just turn it into grass I’m worried it’ll not match and look awful. So thought about planting some flowers/ greenery to cover it up? Something fast growing and sort of covers up the obvious hole. Maybe lavender? Do I need to remove the gravel and put compost on top to even it out? I have another similar section where my paving slabs end that appears to be raised that also looks a mess, I will attach images.

Images attached

You could get some topsoil to bring it up to above grass level then use grass seed or turf.
To plant the area, put some soil improver/ compost down - is the area sunny or in the shade?
If you want the least hassle, plant some tulips/ daffodils that will come up in spring then just scatter different varieties of poppy seeds, they will self seed every year

Thank you, it is in a sunny area, I like tulips so will try that